Manual Chapter : Protecting Against DDoS Attacks

Applies To:

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F5 DDoS Hybrid Defender

14.0.0

Protecting Against DDoS Attacks

Overview: Protecting against DDoS attacks

You can easily set up DDoS Hybrid Defender™ to protect your networks and applications from DoS attacks. Once it is all set up, you can monitor the system to see whether there have been any attacks, and whether they are being handled properly.

Note: You configure DDoS Hybrid Defender by using the settings in the DoS Configuration menu. F5 does not generally recommend making changes using the Advanced Menu.

Protecting the network from DDoS attacks

DDoS Hybrid Defender™ detects and handles DDoS attacks using preconfigured responses. Here you can adjust the device configuration settings that apply to the DDoS Hybrid Defender device as a whole so that it protects the network.

On the Main tab, click DoS Configuration > Device Protection .
From the Log Publisher list, select a destination to which the BIG-IP system sends DoS and DDoS log entries.
You can review, create, and update log publishers in System > Logs > Configuration > Log Publishers .
For Threshold Sensitivity, select Low, Medium, or High.
Low means the automatic threshold calculations are less sensitive to changes in traffic and CPU usage. A lower setting causes the system to adjust the thresholds more slowly over time, but will also trigger fewer false positives. If traffic rates are consistent over time, set this to Medium or High because even a small variation in generally consistent traffic could signal an attack. If traffic patterns vary, set this to Low to get fewer false positives.
From the Eviction Policy list, select the eviction policy to apply globally.

Note: The global context requires an eviction policy. If you do not apply a custom eviction policy, the system default policy, default-eviction-policy is applied and selected in this field.
In the AutoThreshold area, for Relearn, click Start Relearning to start relearning auto-thresholds by analyzing current traffic.
Auto-thresholds are calculated from the system start. If you have made changes to the system since then, and want the system to adjust automatic DoS thresholds because of these changes, use this option.
In the Dynamic Signatures area, for Relearn, click Start Relearning to delete existing dynamic signatures and start learning new ones, by analyzing current traffic. The default learning period is two hours.
Dynamic DoS detection creates dynamic signatures for attacks based on changing traffic patterns over time.

The Learning Phase End Time displays the time and date the last learning period ended.
Optionally, set up appropriate whitelists for addresses that can bypass DDoS checks.
1. To specify a system-wide DoS address list containing addresses that do not need to be checked for DoS attacks, type the name of a previously configured list in the Whitelist Address List field (see Creating a whitelist address list for details). The system must be compatibility level 1 or 2.
  Whitelist address lists are simply lists of addresses.
2. For Rich Whitelists (all compatibility levels), click the Add Whitelist button, type the name, source VLAN, source or destination address, port, and protocol, then click Done Editing.
  You can create up to eight rich whitelists, which allow further delineation of the whitelist.
3. If the system is compatibility level 2, for Extended Whitelists, click the Add Whitelist button, type the name, source VLAN, source address, destination address, port, and protocol, then click Done Editing.
  Extended whitelists can include both the source and destination addresses on systems that support neuron capabilities
Click the edit icon on the right of Network or DNS to open a properties pane where you can configure settings for the family of vectors.
You can specify settings for dynamic signatures, mitigation, or scrubbing.
Click a family (Network, DNS, or SIP) to display the associated attack vectors.
A table opens listing the attack vectors, the properties, and the current device statistics, if available.
In the Attack Type column, click the name of any attack type to edit the settings.
The attack settings appear on the right, in the Properties pane.
By default, the system enforces all of the vectors at some level. To enforce the DoS vector, make sure the State is set to Mitigate (watch, learn, alert, and mitigate).
Other options allow you to Detect Only (watch, learn, and alert) or Learn Only (collect stats, no mitigation).

CAUTION:

For most DoS vectors, you want to enforce the vector. Set a vector to Disabled (no stat collection, no mitigation) only when you find that enforcement of the vector is disrupting legitimate traffic. For example, if you test a legitimate packet with the packet tester and find a DoS vector is preventing packet transmission, you can adjust the thresholds or disable the vector to remedy the issue.
Set the Threshold Mode for the vector.
- If the attack allows automatic threshold configuration, you can select Fully Automatic or Manual Detection/Auto Mitigation to configure automatic or partially automatic thresholds.
- To configure thresholds manually, click Fully Manual.
To set the mitigation state for one or more attack types, select the check box next to the vector name or names, and from the Set State list at the bottom of the screen, select Mitigate, Detect Only, or Disable.
The state you click is set for all selected vectors.
If desired, you can configure threshold settings for multiple DDoS vectors.
1. Select the check box next to the vector names.
2. At the bottom of the screen, click Set Threshold Mode, and choose the threshold setting.
  Select Fully-automatic for the system to set the thresholds for the vectors that use auto-thresholding. See Automatically setting system-wide DDoS thresholds for details.
  
  Note: To work accurately, using fully-automatic thresholds requires some amount of historical data on the system gathered through observing normal traffic. Therefore, it is recommended that you not enforce auto thresholds directly after installation.
  
  To configure thresholds manually, click Manual . See Manually setting system-wide DDoS thresholds for details.
  
  Choose Manual Detection/Auto-Mitigation to configure thresholds manually but have the system automatically mitigate system stress.
When you finish adjusting the settings, click Commit Changes to System.

Now you have configured the device to respond to DoS and DDoS attacks, and to allow such attacks to be identified in system logs and reports.

Refer to the sections on automatically and manually setting system-wide DDoS vector thresholds if you need more details about adjusting the DDoS Hybrid Defender device configuration.

Automatically setting system-wide DDoS vector thresholds

DDoS Hybrid Defender™ handles DDoS attacks at the system level using preconfigured responses, but you might need to adjust the values for your environment. You can configure system-wide device protections that examine all the traffic coming through DDoS Hybrid Defender. For some DDoS attack vectors available in the device protection, you can have the system automatically set detection thresholds and internal rate or leak limits. Use this task to configure individual DoS vectors that include the automatic configuration.

Note: Not all settings apply to all DoS vectors. For example, some vectors do not have automatic thresholds.

On the Main tab, click DoS Configuration > Device Protection .
Click a family (Network, DNS, or SIP) to display the associated attack vectors.
A table opens listing the attack vectors, the properties, and the current device statistics, if available.
In the Attack Type column, click the name of any attack type to edit the settings.
The attack type settings appear on the right, in the Properties pane.
By default, the system enforces all of the vectors at some level. To enforce the DoS vector, make sure the State is set to Mitigate (watch, learn, alert, and mitigate).
Other options allow you to Detect Only (watch, learn, and alert) or Learn Only (collect stats, no mitigation).

CAUTION:

For most DoS vectors, you want to enforce the vector. Set a vector to Disabled (no stat collection, no mitigation) only when you find that enforcement of the vector is disrupting legitimate traffic. For example, if you test a legitimate packet with the packet tester and find a DoS vector is preventing packet transmission, you can adjust the thresholds or disable the vector to remedy the issue.
To allow the DoS vector thresholds to be automatically adjusted, for Threshold Mode, select Fully Automatic (available only for DNS, Flood, SIP, some Fragmentation, and a few other vectors).

Note: Automatic thresholding is not available for every DoS vector. In particular, for error packets that are broken by their nature, such as those listed under Bad Headers, you must configure them manually.
1. In the Attack Floor EPS field, type the number of events per second of the vector type to allow at a minimum, before automatically calculated thresholds are determined.
  Because automatic thresholds take time to be reliably established, this setting defines the minimum packets allowed before automatic thresholds are calculated.
2. In the Attack Ceiling EPS field, specify the absolute maximum allowable for packets of this type before automatically calculated thresholds are determined.
  Because automatic thresholds take time to be reliably established, this setting rate limits packets to the events per second setting, when specified. To set no hard limit, set this to Infinite.
  
  Unless set to infinite, if the maximum number of packets exceeds the ceiling value, the system considers it to be an attack.
To detect IP address sources from which possible attacks originate, enable Bad Actor Detection.
To automatically blacklist bad actor IP addresses, select Add Source Address to Category.
Select the Category Name to which blacklist entries generated by Bad Actor Detection are added.
Specify the Sustained Attack Detection Time, in seconds, after which an IP address is blacklisted.
To change the duration for which the address is blacklisted, specify the duration in seconds in the Category Duration Time field. The default duration for an automatically blacklisted item is 4 hours (14400 seconds).
After this time period, the IP address is removed from the blacklist.
To allow IP source blacklist entries to be advertised to edge routers so they will null route their traffic, select Allow External Advertisement.

Note: To advertise to edge routers, you must configure a Blacklist Publisher for the Advertisement Next-Hop in the Global Settings.
For automatic blacklisting, click Attacked Destination Detection, and configure the additional settings as for Bad Actor Detection.
When you finish adjusting the settings, click Commit Changes to System.

Now you have configured the device to automatically determine DoS attack thresholds based on the characteristics of traffic at the network level. The thresholds assigned are usually between the attack floor and attack ceiling values.

Manually setting system-wide DDoS vector thresholds

You manually configure thresholds for a DDoS vector when you want to configure specific settings, or when the vector does not allow for automatic threshold configuration.

Note: Not all settings apply to all DoS vectors.

On the Main tab, click DoS Configuration > Device Protection .
Click a family (Network, DNS, or SIP) to display the associated attack vectors.
A table opens listing the attack vectors, the properties, and the current device statistics, if available.
In the Attack Type column, click the name of any attack type to edit the settings.
The attack type settings appear on the right, in the Properties pane.
By default, the system enforces all of the attack types at some level. If you do not want to enforce a particular attack type, in the properties set the State to Disabled.
In the Properties pane, set Threshold Mode to Fully Manual.
From the Detection Threshold EPS list, select Specify or Infinite.
- Use Specify to set a value (in packets per second) for the attack detection threshold. If packets of the specified types cross the threshold, an attack is logged and reported. The system continues to check every second, and registers an attack for the duration that the threshold is exceeded.
- Use Infinite to set no value for the threshold.
From the Detection Threshold % list, select Specify or Infinite.
- Use Specify to set a value (in percentage of traffic) for the attack detection threshold. If packets of the specified types cross the percentage threshold, an attack is logged and reported. The system continues to check every second, and registers an attack for the duration that the threshold is exceeded.
- Use Infinite to set no value for the threshold.
From the Mitigation Threshold EPS list, select Specify or Infinite.
- Use Specify to set a value (in events per second), which cannot be exceeded. If the number of events of this type exceeds the threshold, excess events are dropped until the rate no longer exceeds the threshold.
- Use Infinite to set no value for the threshold. This specifies that this type of attack is not rate-limited.
Click Simulate Auto Threshold to log a simulated attacked event that the system identifies as a DoS attack according to the automatic thresholds, though enforcing manual thresholds.

Note: This setting allows you to see the results of auto thresholds on the selected DoS vector without actually affecting traffic. The system displays the current computed thresholds for automatic thresholds for this vector. Automatic thresholds are computed and enforced only when you select Fully Automatic for a vector.
To detect IP address sources from which possible attacks originate, enable Bad Actor Detection.
In the Per Source IP Detection Threshold EPS field, specify the number of packets of this type per second from one IP address that identifies the IP source as a bad actor, for purposes of attack detection and logging.
In the Per Source IP Mitigation Threshold EPS field, specify the number of packets of this type per second from one IP address, above which rate limiting or leak limiting occurs.
To automatically blacklist bad actor IP addresses, select Add Source Address to Category.
Select the Category Name to which blacklist entries generated by Bad Actor Detection are added.
Specify the Sustained Attack Detection Time, in seconds, after which an IP address is blacklisted.
To change the duration for which the address is blacklisted, specify the duration in seconds in the Category Duration Time field. The default duration for an automatically blacklisted item is 4 hours (14400 seconds).
After this time period, the IP address is removed from the blacklist.
To allow IP source blacklist entries to be advertised to edge routers so they will null route their traffic, select Allow External Advertisement.

Note: To advertise to edge routers, you must configure a Blacklist Publisher for the Advertisement Next-Hop in the Global Settings.
For automatic blacklisting, click Attacked Destination Detection, and configure the additional settings as for Bad Actor Detection.
When you finish adjusting the settings, click Commit Changes to System.
Repeat the previous steps for any other attack types for which you want to manually configure thresholds.

Now you have configured the system to provide custom responses to possible DDoS attacks at the device level, and to allow such attacks to be identified in system logs and reports, rate-limited, and blacklisted when specified.

Configuring dynamic signatures at the device level

Dynamic DoS detection creates dynamic signatures for attacks based on changing traffic patterns over time. When an attack is detected, a dynamic signature is created and added to the dynamic signatures list. All packets are then checked against the dynamic signature, and mitigated according to internal logic. You can enable dynamic signatures to dynamically detect and mitigate DoS attacks at the device level for Network or DNS device protection.

On the Main tab, click DoS Configuration > Device Protection .
The DoS Protection Device Configuration screen opens.
To enable dynamic signatures for Network (Layer 3 or 4) or DNS traffic, point to Network or DNS, then select the Edit icon (pencil) that appears on the right side.
The Properties pane opens on the right with the settings for that traffic.
In the Properties pane, for Dynamic Signature Enforcement, from the list, select Enabled.

Note: At first, you may want to select Learn Only to track dynamic signatures, without enforcing any thresholds or limits. Once you see that the system is accurately detecting attacks, then select Enabled.
From the Mitigation Sensitivity list, select the sensitivity level for dropping packets.
- Select None to generate and log dynamic signatures, without dropping packets.
- To drop packets, set the mitigation level from Low to High. A setting of Low is least aggressive, but will also trigger fewer false positives. A setting of High is most aggressive, and the system may drop more false positive packets.
For Network vectors only: To have dynamic signatures handled by an IP Intelligence category, from the Redirection/Scrubbing list, select Enabled.
If using Redirection/Scrubbing to redirect traffic identified by dynamic signatures, from the Scrubbing Category list, select the IP Intelligence category to assign to the scrubbed packets.
In the Scrubbing Advertisement Time field, specify the amount of time during which an IP address remains in the blacklist category (default is 300 seconds).
When you finish adjusting the settings, click Commit Changes to System.
If at any point, you want to delete existing dynamic signatures and restart learning new ones, on the Device Protection screen, click Start Relearning.

With dynamic signatures enabled, the system examines traffic in a learning mode to create a baseline of normal traffic coming to the device. Learning lasts for a couple of hours until sufficient traffic and server stress is analyzed. Then, the system begins anomaly detection and if an attack is detected, it develops dynamic signatures that characterize and mitigate the attack. The system continues to examine traffic patterns in an adaptive mode and constantly updates traffic information and creates dynamic signtures as needed.

To view and edit dynamic signatures, go to the Signatures screen, and click the signature name. You can edit the state and threshold mode, and view predicates in the Properties pane on the right. Click the name in the list again to review details about recent attacks for this signature.

You can also enable dynamic signatures on a protection profile for the protected objects associated with the protection profile.

Creating a whitelist address list

You can specify IP addresses on a whitelist that the system does not check for DDoS attacks. Addresses on the whitelist are trusted IP addresses that are never blocked.

Different types of whitelists are available depending on the hardware compatibility level of your system: whitelists (Level 1 or 2), rich whitelists (all levels), or extended whitelists (Level 2 only). You can create rich and extended whitelists when configuring Device Protection or creating a Protection Profile.

This task describes how to create a Whitelist Address List, which is configurable only if your system compatibility level is set to Level 1 or 2. You can check the compatibility level from the Advanced Menu at System > Configuration > Device > General .

On the Main tab, click DoS Configuration > Whitelist .
Click Create.
In the Name field, type a name.
In the Addresses field, type each address then click Add to add it to the whitelist. Addresses can be in the following forms:
- An IPv4 or IPv6 address, and specify a network with CIDR slash notation
- An IPv4 or IPv6 address range
- A fully qualified domain name
- A geographic location
- Another address list or whitelist
Click Finished to add the whitelist to the configuration.

At the device level, you can use the whitelist in DoS Configuration > Device Protection to specify traffic that is allowed to pass through DDoS Hybrid Defender without undergoing DoS checks. You can also use the whitelist at the profile level in DoS Configuration > Protection Profiles to specify the default or HTTP whitelist.

Adjusting the device compatibility level

You can adjust the compatibility level of the system to enable different levels of DoS protection and whitelists depending on the hardware platform of your system.

Note: If using DDoS Hybrid Defender, adjusting the compatibility level must be done from the Advanced Menu.

On the Main tab, click System > Configuration > Device .

From the Compatibility Level list, select the appropriate compatibility level for your hardware.

Option	Description
LEVEL 0	Specifies a system with basic hardware DoS capabilities (provides device protection and Rich Whitelist). Valid for all systems, and is the default value.
LEVEL 1	Specifies either a VE system with no hardware offload or a system with hardware DoS and sPVA capabilities (in addition to LEVEL 0 features provides hardware DoS protection per protected object, Whitelist Address List, IP intelligence, and bad actor/attacked destination discovery).
LEVEL 2	Specifies a system with hardware DoS, sPVA, and Neuron capabilities (in addition to LEVEL 1 features provides extended whitelist).

You will receive a message if you select a level that is not applicable to your hardware.

Click Update.

Traffic from the trusted IP addresses is allowed to pass through DDoS Hybrid Defender, and does not undergo DoS checks.

Creating a protection profile

You need to create a DoS protection profile to define which protection mechanisms to apply to specific protected objects in your network. You can apply one protection profile to multiple protected objects, if they have similar characteristics.

For example, if securing a DNS server and several application servers, you could create two protection profiles: one that enforces DNS vectors and the other for enforcing HTTP vectors on two application servers. Then, you can create three protected objects and associate the DNS protection profile with the protected object representing the DNS server, and associate the HTTP protection profile with the protected objects created for the application servers.

On the Main tab, click DoS Configuration > Protection Profiles .
Click Create.
The Create New Protection Profile screen opens.
In the Name field, type a name.
In the Description field, optionally type a description.
Select the Threshold Sensitivity.
Select Low, Medium, or High. A lower setting means the automatic threshold algorithm is less sensitive to changes in traffic and CPU usage, but will also trigger fewer false positives.
If you have created a whitelist on the system, from the Default Whitelist list, select the list.
You can also click Manage Address Lists to jump to the Address Lists screen where you can create or edit address lists.
For HTTP Whitelist, you can use the default HTTP whitelist or Override Default to specify another list.
For Families, select the types of vectors to include in the protection profile.
Click the edit icon on the right of Network or DNS to open a properties pane where you can configure settings for the family of vectors.
You can specify settings for dynamic signatures, mitigation, or scrubbing.
Click a family (Network, DNS, SIP, or HTTP) to display the associated attack vectors.
A table opens listing the attack vectors, the properties, and the current device statistics, if available.
In the Vector Name column, click the name of any vector to edit the settings.
The vector settings appear on the right, in the Properties pane.
To fully enforce the DoS vector, make sure the State is set to Mitigate (watch, learn, alert, and mitigate).
Other options allow you to Detect Only (watch, learn, and alert) or Learn Only (collect stats, no mitigation).

Note: If you have enforced most of the vectors at the device level using Device Protection, you can focus on adjusting the vector thresholds that vary for specific protected objects.
Set the Threshold Mode for the vector.
- If the attack allows automatic threshold configuration, you can select Fully Automatic or Manual Detection/Auto Mitigation to configure automatic or partially automatic thresholds.
- To configure thresholds manually, click Fully Manual.
To set the mitigation state for one or more attack types, select the check box next to the vector name or names, and from the Set State list at the bottom of the screen, select Mitigate, Detect Only, or Disable.
The state you click is set for all selected vectors.
If desired, you can configure threshold settings for multiple DDoS vectors.
1. Select the check box next to the vector names.
2. At the bottom of the screen, click Set Threshold Mode, and choose the threshold setting.
  Select Fully-automatic for the system to set the thresholds for the vectors that use auto-thresholding. See Automatically setting DDoS thresholds for Protected Objects for details.
  
  Note: To work accurately, using fully automatic thresholds requires some amount of historical data on the system gathered through observing normal traffic. Therefore, it is recommended that you not enforce auto thresholds directly after installation.
  
  To configure thresholds manually, click Manual . See Manually setting DDoS thresholds for protected objects for details.
  
  Choose Manual Detection/Auto-Mitigation to configure thresholds manually but have the system automatically mitigate system stress.
When you finish adjusting the settings of the vectors, click Commit Changes to System.
The protection profile is created.

You have created a protection profile that implements specific DoS protections.

Next, you need to attach the protection profile to one or more protected objects.

Automatically setting DDoS vector thresholds for protected objects

DDoS Hybrid Defender™ protects network objects from DoS attacks by using a protection profile that you assign to protected objects. The protection profile is where you define thresholds for DDoS attack vectors. For some attack vectors in the protection profile, the system can automatically set detection thresholds and internal rate or leak limits by examining traffic patterns. Use this task to configure individual DoS vectors that include the automatic configuration.

Note: Not all settings apply to all DoS vectors. For example, some vectors do not have automatic thresholds.

On the Main tab, click DoS Configuration > Protection Profiles .
Click the name of the protection profile to edit, or create a new one.
For Families, select the types of vectors to include in the protection profile.
Click a family (Network, DNS, SIP, or HTTP) to display the associated attack vectors.
A table opens listing the attack vectors, the properties, and the current device statistics, if available.
In the Vector Name column, click the name of any vector to edit the settings.
The vector settings appear on the right, in the Properties pane.
To fully enforce the DoS vector, make sure the State is set to Mitigate (watch, learn, alert, and mitigate).
Other options allow you to Detect Only (watch, learn, and alert) or Learn Only (collect stats, no mitigation).

Note: If you have enforced most of the vectors at the device level using Device Protection, you can focus on adjusting the vector thresholds that vary for specific protected objects.
To allow the DoS vector thresholds to be automatically adjusted, for Threshold Mode, select Fully Automatic (available only for DNS, Flood, SIP, some Fragmentation, and a few other vectors).

Note: Automatic thresholding is not available for every DoS vector. In particular, for error packets that are broken by their nature, such as those listed under Bad Headers, you must configure them manually.
1. In the Attack Floor EPS field, type the number of events per second of the vector type to allow at a minimum, before automatically calculated thresholds are determined.
  Because automatic thresholds take time to be reliably established, this setting defines the minimum packets allowed before automatic thresholds are calculated.
2. In the Attack Ceiling EPS field, specify the absolute maximum allowable for packets of this type before automatically calculated thresholds are determined.
  Because automatic thresholds take time to be reliably established, this setting rate limits packets to the events per second setting, when specified. To set no hard limit, set this to Infinite.
  
  Unless set to infinite, if the maximum number of packets exceeds the ceiling value, the system considers it to be an attack.
To detect IP address sources from which possible attacks originate, enable Bad Actor Detection.
To automatically blacklist bad actor IP addresses, select Add Source Address to Category.
Select the Category Name to which blacklist entries generated by Bad Actor Detection are added.
Specify the Sustained Attack Detection Time, in seconds, after which an IP address is blacklisted.
To change the duration for which the address is blacklisted, specify the duration in seconds in the Category Duration Time field. The default duration for an automatically blacklisted item is 4 hours (14400 seconds).
After this time period, the IP address is removed from the blacklist.
To allow IP source blacklist entries to be advertised to edge routers so they will null route their traffic, select Allow External Advertisement.

Note: To advertise to edge routers, you must configure a Blacklist Publisher for the Advertisement Next-Hop in the Global Settings.
For automatic blacklisting, click Attacked Destination Detection, and configure the additional settings as for Bad Actor Detection.
When you finish adjusting the settings, click Commit Changes to System.

Now you have configured the protection profile to automatically determine DoS attack thresholds based on the characteristics of traffic. The thresholds assigned are usually between the attack floor and attack ceiling values.

Next, you need to attach the protection profile to one or more protected objects.

Manually setting DDoS vector thresholds for protected objects

You manually configure thresholds for a DDoS vector in a protection profilewhen you want to configure specific settings, or when the vector does not allow for automatic threshold configuration.

Note: Not all settings apply to all DoS vectors.

On the Main tab, click DoS Configuration > Protection Profiles .
Click the name of the protection profile to edit, or create a new one.
For Families, select the types of vectors to include in the protection profile.
Click a family (Network, DNS, SIP, or HTTP) to display the associated attack vectors.
A table opens listing the attack vectors, the properties, and the current device statistics, if available.
In the Vector Name column, click the name of any vector to edit the settings.
The vector settings appear on the right, in the Properties pane.
To fully enforce the DoS vector, make sure the State is set to Mitigate (watch, learn, alert, and mitigate).
Other options allow you to Detect Only (watch, learn, and alert) or Learn Only (collect stats, no mitigation).

Note: If you have enforced most of the vectors at the device level using Device Protection, you can focus on adjusting the vector thresholds that vary for specific protected objects.
In the Properties pane, set Threshold Mode to Fully Manual.
From the Detection Threshold EPS list, select Specify or Infinite.
- Use Specify to set a value (in packets per second) for the attack detection threshold. If packets of the specified types cross the threshold, an attack is logged and reported. The system continues to check every second, and registers an attack for the duration that the threshold is exceeded.
- Use Infinite to set no value for the threshold.
From the Detection Threshold % list, select Specify or Infinite.
- Use Specify to set a value (in percentage of traffic) for the attack detection threshold. If packets of the specified types cross the percentage threshold, an attack is logged and reported. The system continues to check every second, and registers an attack for the duration that the threshold is exceeded.
- Use Infinite to set no value for the threshold.
From the Mitigation Threshold EPS list, select Specify or Infinite.
- Use Specify to set a value (in events per second), which cannot be exceeded. If the number of events of this type exceeds the threshold, excess events are dropped until the rate no longer exceeds the threshold.
- Use Infinite to set no value for the threshold. This specifies that this type of attack is not rate-limited.
Click Simulate Auto Threshold to log a simulated attacked event that the system identifies as a DoS attack according to the automatic thresholds, though enforcing manual thresholds.

Note: This setting allows you to see the results of auto thresholds on the selected DoS vector without actually affecting traffic. The system displays the current computed thresholds for automatic thresholds for this vector. Automatic thresholds are computed and enforced only when you select Fully Automatic for a vector.
To detect IP address sources from which possible attacks originate, enable Bad Actor Detection.
In the Per Source IP Detection Threshold EPS field, specify the number of packets of this type per second from one IP address that identifies the IP source as a bad actor, for purposes of attack detection and logging.
In the Per Source IP Mitigation Threshold EPS field, specify the number of packets of this type per second from one IP address, above which rate limiting or leak limiting occurs.
To automatically blacklist bad actor IP addresses, select Add Source Address to Category.
Select the Category Name to which blacklist entries generated by Bad Actor Detection are added.
Specify the Sustained Attack Detection Time, in seconds, after which an IP address is blacklisted.
To change the duration for which the address is blacklisted, specify the duration in seconds in the Category Duration Time field. The default duration for an automatically blacklisted item is 4 hours (14400 seconds).
After this time period, the IP address is removed from the blacklist.
To allow IP source blacklist entries to be advertised to edge routers so they will null route their traffic, select Allow External Advertisement.

Note: To advertise to edge routers, you must configure a Blacklist Publisher for the Advertisement Next-Hop in the Global Settings.
For automatic blacklisting, click Attacked Destination Detection, and configure the additional settings as for Bad Actor Detection.
When you finish adjusting the settings, click Commit Changes to System.
Repeat the previous steps for any other attack types for which you want to manually configure thresholds.

Now you have configured the protection profile to provide custom responses to possible DDoS attacks on protected objects, and to allow such attacks to be identified in system logs and reports, rate-limited, and blacklisted, when the protection profile is attached to one or more protected objects.

Configuring dynamic signatures in the protection profile

Dynamic DoS detection creates dynamic signatures that define attacks based on changing traffic patterns over time. When an attack is detected, a dynamic signature is created and added to the dynamic signatures list. All packets are then checked against the dynamic signature, and mitigated according to internal logic. You enable dynamic signatures in a protection profile to dynamically detect and mitigate DoS attacks for protected objects that are associated with the profile.

On the Main tab, click DoS Configuration > Protection Profiles .
To enable dynamic signatures for Network (Layer 3 or 4) or DNS traffic, point to Network or DNS, then select the Edit icon (pencil) that appears on the right side.
The Properties pane opens on the right.
In the Properties pane, for Dynamic Signature Enforcement, from the list, select Enabled.

Note: At first, you may want to select Learn Only to track dynamic signatures, without enforcing any thresholds or limits. Once you see that the system is accurately detecting attacks, then select Enabled.
From the Mitigation Sensitivity list, select the sensitivity level for dropping packets.
- Select None to generate and log dynamic signatures, without dropping packets.
- To drop packets, set the mitigation level from Low to High. A setting of Low is least aggressive, but will also trigger fewer false positives. A setting of High is most aggressive, and the system may drop more false positive packets.
For Network vectors only: To have dynamic signatures handled by an IP Intelligence category, from the Redirection/Scrubbing list, select Enabled.
If using Redirection/Scrubbing to redirect traffic identified by dynamic signatures, from the Scrubbing Category list, select the IP Intelligence category to assign to the scrubbed packets.
In the Scrubbing Advertisement Time field, specify the amount of time during which an IP address remains in the blacklist category (default is 300 seconds).
When you finish adjusting the settings, click Commit Changes to System.
If at any point, you want to delete existing dynamic signatures for this protected object and restart learning new ones:
1. On the Main tab, click Local Traffic > Virtual Servers . (For DDoS, use the Advanced Menu.)
2. Click the name of the protected object for which you want to remove dynamic signatures.
3. Select Security > Policies .
4. In the Dynamic Signatures field, click Relearn.

With dynamic signatures enabled, the system examines traffic in learning mode to create a baseline of normal traffic coming to the device. Learning lasts for a couple of hours until sufficient traffic and server stress is analyzed. Then, the system begins anomaly detection and if an attack is detected, it develops dynamic signatures that characterize and mitigate the attack. The system continues to examine traffic patterns in an adaptive mode and constantly updates traffic information, and developing dynamic signatures as needed.

You can also enable dynamic signatures for network or DNS traffic at the device level.

Protecting network objects from DDoS attacks

With DDoS Hybrid Defender™, you can protect different types of network devices such as application servers, network hosts, DNS servers, routers, and so on against DDoS attacks. These network devices are called protected objects.

You need to create protected objects that represent the different devices, and attach a protection profile that defines the DoS protections to apply to that device.

On the Main tab, click DoS Configuration > Protected Objects .
The Protected Objects screen is displayed showing the configured protected objects.
On the far right, click Create > Protected Object .
The Properties pane opens on the right where you create the protected object. The Shared Objects pane also appears and that is where you can develop traffic matching criteria for Netflow Protected Servers. It does not apply to Protected Objects.
In the Properties pane, for Name, type a name for the protected object.
In the Source Address field, type the IP address or network from which the protected object accepts traffic.
Specify the IP address in CIDR format: address/prefix, where the prefix length is in bits: for example, for IPv4: 10.0.0.1/32 or 10.0.0.0/24, and for IPv6: ffe1::0020/64 or 2001:ed8:77b5:2:10:10:100:42/64.
In the Destination Address field, type the IP address or network to which the protected object can send traffic (same format as source address).
In the Service Port field, type the service port used by the protected object, or select a type from the list.
In the Throughput Capacity (Mbps) field, type the maximum allowable throughput in megabits per second for the protected object. Infinite means no limit.
From the Protocol list, select the network protocol that the protected object uses. Options are: TCP, UDP, or All Protocols.
From the Service Profile list, select the appropriate DNS, SIP, or HTTP service profile to associate with the protected object.
In most cases, the default DHD_dns, DHD_sip, or DHD_http profile is sufficient. To adjust the profile settings, from the Advanced Menu, select Local Traffic > Profiles > Services and select DNS, SIP (legacy), or HTTP. From there, you can edit the default profiles or create new ones.
From the Protection Profile list, select the protection profile that defines the protections and thresholds to associate with the protected object.
From the Eviction Policy list, select the eviction policy to associate with the protected object.
The eviction policy provides guidelines for how aggressively the system discards flows from the flow table.
From the IP Intelligence list, select the IP intelligence policy to associate with the protected object.
The IP intelligence policy checks traffic against an IP intelligence database that contains known bad or questionable IP addresses.
From the VLANs list, move one or more VLANs available to this protected object into the Selected list.

Tip: You can view and create VLANs by clicking View VLAN Profiles.
From the Logging Profiles list, move one or more log profiles to use for this protected object into the Selected list.

Tip: You can view and create Logging Profiles by clicking View Log Profiles.
Click the Save button.
The system creates the protected object.

Now you have configured the system to protect a network object from DDoS attacks, and to allow such attacks to be identified in system logs and reports.

Creating an eviction policy

You can create eviction policies to control the granularity and aggressiveness with which the system discards flows.

On the Main tab, click DoS Configuration > Eviction Policy .
In the Name field, type a name for the eviction policy.
In the Trigger fields, type a high and low water mark for the eviction policy.
This measure specifies the percentage of the quota, for this context, before flow eviction starts (high water mark) and ends (low water mark).
Enable Slow Flow Monitoring to monitor flows that are considered slow by the system, and specify the slow flow threshold in bytes per second.
This combination of settings monitors the system for flows that fall below the slow flow threshold for more than 30 seconds.
In the Grace Period field you can set a grace period, in seconds, between the detection of slow flows that meet the threshold requirement, and purging of slow flows according to the Slow Flow Throttling settings.

In the Slow Flow Throttling area, set the slow flow throttling options.

Option	Description
Disabled	Slow flows are monitored, but not removed from the system when the threshold requirement is met for 30 seconds.
Absolute	Slow flows are removed from the system when the threshold requirement is met for 30 seconds. Setting an absolute limit removes all slow flows beyond the specified absolute number of flows.
Percent	Slow flows are removed from the system when the threshold requirement is met for 30 seconds. Setting a percentage limit removes that percentage of slow flows that exceed the specified monitoring setting, so the default value of 100% removes all slow flows that exceed the slow flow threshold, after the grace period.

For Strategies, configure the strategies that the eviction policy uses to remove flows by moving algorithms from the Available list to the Selected list.
Click Finished.

The eviction policy appears in the Eviction Policy List.

To use an eviction policy, associate it with a protected object or a route domain. You can configure a global eviction policy at System > Configuration > Local Traffic > General .

Creating a policy to check addresses against IP intelligence

You can verify IP addresses against the preconfigured IP Intelligence database, and against IPs from your own feed lists, by creating an IP Intelligence policy.

On the Main tab, click DoS Setup > IP Intelligence > Policies .
The IP Intelligence Policies screen opens.
Click Create to create a new IP Intelligence policy.
In the Name field, type a name for the IP intelligence policy.
For Default Action, set the default action for the IP intelligence policy as a whole.
- Select Accept to allow packets from categorized addresses that have no action applied on the feed list.
- Select Drop to drop packets from categorized addresses that have no action applied on the feed list.
The default action applies to addresses that are not assigned a blacklist category in the feed list. The IP Intelligence feature uses the action specified in a feed list entry, when available.
Set Default Log Actions for the IP intelligence policy as a whole.
- Log Whitelist Overrides logs only whitelist matches that override blacklist matches.
- Log Blacklist Category Matches logs IP addresses that match blacklist categories.
- Select both Log Blacklist Category Matches and Log Whitelist Overrides to log all blacklist matches, and all whitelist matches that override blacklist matches.
Note: Whitelist matches always override blacklist matches.
To customize default actions and logging for any of the blacklist categories, specify default actions in the Blacklist Matching Policy setting.

Note: The default action for a blacklist category is always Reject.

For each category that you want to customize:
1. From the Blacklist Category list, select a category.
2. For Action, select Use Policy Default to use the default action for this policy; select Drop to drop packets from sources of the specified type, as identified by the IP address intelligence database; or select Accept to allow packets in this category.
3. For Log Blacklist Category Matches, select Use Policy Default to use the default log action for blacklist matches; Yes affords visibility into blacklist matches and logs all packets, but provides no hardware acceleration data; Limited logs statistics every 256 packets and includes hardware acceleration; No does not log blacklist matches but provides the highest performance with hardware acceleration.
4. For Log Whitelist Overrides, select Use Policy Default to use the default log action for whitelist overrides; select Yes or No to override the default action.
5. For Match Override, select the matching criteria that overrides a blacklist match. You can require a source match, a destination match, or both a source and destination match to override a blacklist match with a whitelist.
6. Click Add to add the custom defaults for the category.
  You can also select Replace to replace the defaults for a category.
7. Repeat these steps for any category for which you want to customize default actions.
The custom categories are listed at the bottom. You can select and delete them if things change.
Click Finished.

You created an IP intelligence policy. Next, it needs to be assigned globally to the BIG-IP system, to a specific virtual server, or a route domain so that it is applied to the correct traffic.

How to protect different network objects from DDoS attacks

Administrators often want to protect against a specific type of DDoS attack or to protect a particular type of protected object from attacks. This table gives you an idea of the types of protections you can set up.

To protect this:	Use these settings:
DNS Servers	Create a protection profile for all DNS Servers. In Families, click DNS. Expand DNS, check threshold settings. Create a protected object for each DNS Server. Set Service Port to the DNS port. Set Protocol to UDP. In Protection Profile, select the profile you created.
SIP Servers	Create a protection profile for all SIP Servers. In Families, click SIP. Expand SIP, check threshold settings. Create a protected object for each SIP Server. Set Service Port to the SIP port. Set Protocol to TCP. In Protection Profile, select the profile you created.
Web applications	Create a protection profile for one or more application servers. In Families, click HTTP. Expand HTTP, check threshold settings. Create a protected object for each application server. Set Service Port to `80` for HTTP. Set Protocol to TCP. In Protection Profile, select the profile you created.
Backend servers from Syn Floods	Create a protection profile for all backend servers. In Families, click Network. Expand Network, check the settings for TCP SYN Flood. Create a protected object for each backend server. Set Destination Address to `` for all addresses. Set Service Port to `` for all ports. Set Protocol to TCP. In Protection Profile, select the profile you created.
Backend servers from Sweep Attacks	Create a protection profile for all backend servers. In Families, click Network. Expand Network, for Sweep select the packet types to check for sweep attacks. Create a protected object for each backend server. Set Destination Address to `` for all addresses. Set Port to `` for all ports. Set VLAN to `defaultVLAN` . Set Protocol to TCP. In Protection Profile, select the profile you created.

DDoS protected object attack types

For each protected object, you can specify specific threshold, rate increase, rate limit, and other parameters for supported DoS attack types, to more accurately detect, track, and rate limit attacks.

IPv4 Attack Vectors

Vector	Information
Host Unreachable	The host cannot be reached.
ICMP Fragment	ICMP fragment flood.
ICMPv4 Flood	Flood with ICMPv4 packets.
IP Fragment Flood	Fragmented packet flood with IPv4.
IP Option Frames	IPv4 address packets that are part of an IP option frame flood. On the command line `option.db variable tm.acceptipsourceroute` must be enabled to receive IP options.
TIDCMP	ICMP type 4 error; can't accept queries.
TTL <= `tunable`	An IP packet with a destination that is not multicast has a Time to live (TTL) value less than or equal to the configured value. To tune this value, in tmsh: `modify sys db dos.iplowttl` `value`, where `value` is 1-4. 1 is default.

IPv6 Attack Vectors

Vector	Information
Host Unreachable	The host cannot be reached.
ICMP Fragment	ICMP fragment flood.
ICMPv6 Flood	Flood with ICMPv6 packets.
IPV6 Extended Header Frames	IPv6 address contains extended header frames.
IPv6 extension header too large	An IPv6 extension header exceeds the limit in bytes set at DoS Protection > Quick Configuration > Global Settings , in the Too Large IPv6 Extension Header field .
IPV6 Fragment Flood	The IPv6 extended header hop count is less than or equal to the hop count limit set at DoS Protection Quick Configuration Global Settings, in the IPv6 Low Hop Count field.
IPv6 hop count <= <tunable>	The IPv6 extended header hop count is less than or equal to the hop count limit set at DoS Protection Quick Configuration Global Settings, in the IPv6 Low Hop Count field.
Too Many Extended Headers	For an IPv6 address, the extension headers exceed the limit set at DoS Protection > Quick Configuration > Global Settings , in the Too Many IPv6 Extension Header field.

TCP Attack Vectors

Vector	Information
Non TCP Connection	Sets a connection rate limit for non-TCP flows that takes into account all other connections per second.
Option Present With Illegal Length	Packets contain an option with an illegal length.
TCP Bad URG	TCP header has a bad URG flag, this is likely malicious (flag is set and urgent pointer is 0).
TCP Option Overruns TCP Header	The TCP option bits overrun the TCP header.
TCP PSH Flood	Attackers send spoofed PUSH packets at very high rates; packets do not belong to any current session.
TCP RST Flood	TCP reset attack, also known as "forged TCP resets", "spoofed TCP reset packets" or "TCP reset attacks" is a method of tampering with Internet communications.
TCP SYN ACK Flood	An attack method that involves sending a target server spoofed SYN-ACK packets at a high rate.
TCP SYN Flood	Attackers send a succession of SYN requests to a target's system in an attempt to consume enough server resources to make the system unresponsive to legitimate traffic.
TCP SYN Oversize	Detects TCP data SYN packets larger than the maximum specified in the limit set at DoS Protection > Quick Configuration > Global Settings , in the Too Large TCP SYN Packet field. The default size in bytes is `64` and the maximum allowable value is `9216`.
TCP Window Size	The TCP window size in packets is above the maximum size. To tune this setting, change the setting at Dos Protection > Quick Configuration > Global Settings , in the Too Low TCP Window Size field.
Unknown TCP Option Type	TCP option type is not standard.

UDP Attack Vector

Vector	Information
UDP Flood	The attacker sends UDP packets, typically large ones, to single destination or to random ports.

Sweep Attack Vector

Vector	Information
Sweep	The attacker uses a network scanning technique that typically sweeps your network by sending packets, and using the packet responses to determine live hosts.

DNS Attack Vectors

Vector	How to identify it
a	UDP packet, DNS Qtype is A_QRY, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
aaaa	UDP packet, DNS Qtype is AAAA, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
any	UDP packet, DNS Qtype is ANY_QRY, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
axfr	UDP packet, DNS Qtype is AXFR, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
cname	UDP DNS query, DNS Qtype is CNAME, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
dns-malformed	Malformed DNS packets.
ixfr	UDP DNS query, DNS Qtype is IXFR, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
mx	UDP DNS query, DNS Qtype is MX, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
ns	UDP DNS query, DNS Qtype is NS, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
other	UDP DNS query, DNS Qtype is OTHER, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
ptr	UDP DNS query, DNS Qtype is PTR, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
qdcount	DNS QDCount limit. UDP packet, DNS qdcount neq 1, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
soa	UDP packet, DNS Qtype is SOA_QRY, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
srv	UDP packet, DNS Qtype is SRV, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).
txt	UDP packet, DNS Qtype is TXT, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Protection > Quick Configuration > Global Settings to the DNS VLAN (`0-4094`).

SIP Attack Vectors

Vector	Information
ack	SIP ACK packets. Used with invite request when establishing a call.
bye	SIP BYE packets. The attacker tries to terminate a communication session prematurely.
cancel	SIP CANCEL packets. Attackers prevent callers from establishing a session.
invite	SIP INVITE packets. Attackers send multiple invite packets to initiate call sessions.
message	SIP MESSAGE packets. Attackers send instant messages.
notify	SIP NOTIFY packets. Attackers send notifications, such as of voice mails.
options	SIP OPTIONS packets. Attackers send probes to determine capabilities of servers.
other	Other SIP method packets.
prack	SIP PRACK packets. Attackers send prack packets for provisional acknowledgements.
publish	SIP PUBLISH packets. Attackers publish messages to the server.
register	SIP REGISTER packets. Attackers register or unregister a phone address listed in the To header field with a SIP server.
subscribe	SIP SUBSCRIBE packets. Attackers send subscriber notification messages.
URI Limit	The SIP URI exceeds the limit set at Dos Protection > Quick Configuration > Global Settings , in the Too Long SIP URI field. This setting should be less than `1024`, the maximum length for a SIP URI in bytes.

Layer 7 HTTP and HTTPS Attack Vectors

Protection	Description
Behavioral	Attack indicates bad actors by their anomalous behavior based on deviation from baseline behavior.
Detection by Device	Attack indicates suspicious client devices tracked by fingerprinting and a high number of transactions per second.
Detection by Geolocation	Attack indicates suspicious geographical locations identified by their IP range and an unusual traffic share.
Detection by Site	Attack indicates that the global traffic on the site (whole application) signifies an attack based on a high number of transactions per second.
Detection by Source-IP	Attack indicates suspicious clients identified by their IP address and a high number of transactions per second.
Detection by URL	Attack targets specific URLs in the web application by sending a high number of transactions per second to them.
Heavy URL	Attack focuses on URLs that consume considerable server resources thus can become tipping points in DoS attacks. The system automatically detects heavy URLs.

HTTP and HTTPS Proactive Bot Defense Categories

Category	Description/Category
Proactive Bot Defense	Attacks caused by web robots. The system uses JavaScript evaluations and bot signatures to ensure that browsers are legitimate not automated.
Crawler	Benign
HTTP Library	Benign
Search Bot	Benign
Search Engine	Benign
Service Agent	Benign
Site Monitor	Benign
Social Media Agent	Benign
Web Downloader	Benign
DoS Tool	Malicious
E-Mail Collector	Malicious
Exploit Tool	Malicious
Network Scanner	Malicious
Spam Bot	Malicious
Vulnerability Scanner	Malicious
Web Spider	Malicious

DDoS device protection attack types

In Device Protection, you can specify thresholds, rate increase, rate limit, and other parameters for device-level DDoS attack types, to more accurately detect, track, and rate limit attacks. Broken packets, such as those with bad headers, should be severely rate limited.

Network attack types

Vector	Information	Hardware accelerated
ARP Flood	ARP packet flood	Yes
Bad ICMP Checksum	An ICMP frame checksum is bad. Reuse the TCP or UDP checksum bits in the packet.	Yes
Bad ICMP Frame	The ICMP frame is either the wrong size or not one of the valid IPv4 or IPv6 types. Valid IPv4 types: 0 Echo Reply 3 Destination Unreachable 4 Source Quench 5 Redirect 8 Echo 11 Time Exceeded 12 Parameter Problem 13 Timestamp 14 Timestamp Reply 15 Information Request 16 Information Reply 17 Address Mask Request 18 Address Mask Reply Valid IPv6 types: 1 Destination Unreachable 2 Packet Too Big 3 Time Exceeded 4 Parameter Problem 128 Echo Request 129 Echo Reply 130 Membership Query 131 Membership Report 132 Membership Reduction	Yes
Bad IGMP Frame	IPv4 IGMP packets should have a header >= 8 bytes. Bits 7:0 should be either 0x11, 0x12, 0x16, 0x22 or 0x17, or else the header is bad. Bits 15:8 should be non-zero only if bits 7:0 are 0x11, or else the header is bad.	Yes
Bad IP TTL Value	Time-to-live equals zero for an IPv4 address.	Yes
Bad IP Version	The IPv4 address version in the IP header is not 4.	Yes
Bad IPv6 Addr	IPv6 source IP = `0xff00::`	Yes
Bad IPV6 Hop Count	Both the terminated (cnt=0) and forwarding packet (cnt=1) counts are bad.	Yes
Bad IPV6 Version	The IPv6 address version in the IP header is not 6.	Yes
Bad SCTP Checksum	Bad SCTP packet checksum.	No
Bad Source	The IPv4 source IP = `255.255.255.255` or `0xe0000000U`.	Yes
Bad TCP Checksum	The TCP checksum does not match.	Yes
Bad TCP Flags (All Cleared)	Bad TCP flags (all cleared and SEQ#=0).	Yes
Bad TCP Flags (All Flags Set)	Bad TCP flags (all flags set).	Yes
Bad UDP Checksum	The UDP checksum is not correct.	Yes
Bad UDP Header (UDP Length > IP Length or L2 Length)	UDP length is greater than IP length or Layer 2 length.	Yes
Ethernet MAC Source Address == Destination Address	Ethernet MAC source address equals the destination address.	Yes
FIN Only Set	Bad TCP flags (only FIN is set).	Yes
Header Length > L2 Length	No room in Layer 2 packet for IP header (including options) for IPv4 address	Yes
Header Length Too Short	IPv4 header length is less than 20 bytes.	Yes
Host Unreachable	Host unreachable error	Yes
ICMP Fragment	ICMP fragment flood	Yes
ICMP Frame Too Large	The ICMP frame exceeds the declared IP data length or the maximum datagram length set at DoS Setup > Global , in the Too Large IPv6 Extension Header field. To tune this value, in tmsh: `modify sys db dos.maxicmpframesize value`, where `value` is <=`65515`.	Yes
ICMPv4 Flood	Flood with ICMPv4 packets	Yes
ICMPv6 Flood	Flood with ICMPv6 packets	Yes
IGMP Flood	Flood with IGMP packets (IPv4 packets with IP protocol number 2)	Yes
IGMP Fragment Flood	Fragmented packet flood with IGMP protocol	Yes
IP Error Checksum	The header checksum is not correct.	Yes
IP Fragment Error	Other IPv4 fragment error	Yes
IP Fragment Flood	Fragmented packet flood with IPv4	Yes
IP Fragment Overlap	IPv4 overlapping fragment error	No
IP Fragment Too Small	IPv4 short fragment error	Yes
IP Length > L2 Length	The total length in the IPv4 address header or payload length in the IPv6 address header is greater than the Layer 3 length in a Layer 2 packet.	Yes
IP Option Frames	IPv4 address packets that are part of an IP option frame flood. On the command line `option.db variable tm.acceptipsourceroute` must be enabled to receive IP options.	Yes
IP Option Illegal Length	Option present with illegal length.	No
IP uncommon proto	Sets thresholds for and tracks packets containing IP protocols considered to be uncommon. By default, all IP protocols other than TCP, UDP, ICMP, IPV6-ICMP, and SCTP are on the IP uncommon protocol list.	Yes
IP Unknown protocol	Unknown IP protocol	No
IPv4 mapped IPv6	The IPv6 stack is receiving IPv4 address packets.	Yes
IPV6 Atomic Fragment	IPv6 Frag header present with M=0 and FragOffset =0	Yes
IPv6 duplicate extension headers	An extension header should occur only once in an IPv6 packet, except for the Destination Options extension header.	Yes
IPv6 Extended Header Frames	IPv6 address contains extended header frames.	Yes
IPv6 extended headers wrong order	Extension headers in the IPv6 header are in the wrong order.	Yes
IPv6 extension header too large	An IPv6 extension header exceeds the limit in bytes set at DoS Setup > Global , in the Too Large IPv6 Extension Header field.	Yes
IPv6 Fragment Error	Other IPv6 fragment error	Yes
IPv6 Fragment Flood	Fragmented packet flood with IPv6	Yes
IPv6 Fragment Overlap	IPv6 overlapping fragment error	No
IPv6 Fragment Too Small	IPv6 short fragment error	Yes
IPv6 hop count <= <tunable>	The IPv6 extended header hop count is less than or equal to the hop count limit set at DoS Setup > Global , in the IPv6 Low Hop Count field.	Yes
IPv6 Length > L2 Length	IPv6 address length is greater than the Layer 2 length.	Yes
L2 Length >> IP Length	Layer 2 packet length is much greater than the payload length in an IPv4 address header, and the Layer 2 length is greater than the minimum packet size.	Yes
LAND Attack	Source IP equals destination IP address	Yes
No L4	No Layer 4 payload for IPv4 address.	Yes
No L4 (Extended Headers Go To Or Past End of Frame)	Extended headers go to the end or past the end of the L4 frame.	Yes
No Listener Match	This can occur if the listener is down as it attempts to make a connection, or if it was not started or was configured improperly. It may also be caused by a network connectivity problem.
Non TCP Connection	Sets a connection rate limit for non-TCP flows that takes into account all other connections per second.
Option Present With Illegal Length	Packets contain an option with an illegal length.	Yes
Payload Length < L2 Length	Specified IPv6 payload length is less than the L2 packet length.	Yes
Routing Header Type 0	Identifies flood packets containing type 0 routing headers, which can be used to amplify traffic to initiate a DoS attack.	Yes
Single Endpoint Flood	Flood to a single endpoint and can come from many sources. You can configure packet types to check for, and packets per second for both detection and rate limiting.	No
Single Endpoint Sweep	Sweep on a single endpoint. You can configure packet types to check for, and packets per second for both detection and rate limiting.	No
SYN && FIN Set	Bad TCP flags (SYN and FIN set).	Yes
TCP BADACK Flood	TCP ACK packet flood	No
TCP Flags - Bad URG	Packet contains a bad URG flag; this is likely malicious.	Yes
TCP Half Open	TCP connection whose state is out of synchronization between the two communicating hosts	Yes
TCP Header Length > L2 Length	The TCP header length exceeds the Layer 2 length.	Yes
TCP Header Length Too Short (Length < 5)	The Data Offset value in the TCP header is less than five 32-bit words.	Yes
TCP Option Overruns TCP Header	The TCP option bits overrun the TCP header.	Yes
TCP PUSH Flood	TCP PUSH flood	Yes
TCP RST Flood	TCP RST flood	Yes
TCP SYN ACK Flood	TCP SYN/ACK flood	Yes
TCP SYN Flood	TCP SYN flood	Yes
TCP SYN Oversize	Detects TCP data SYN packets larger than the maximum specified in the limit set at DoS Setup > Global , in the Too Large TCP SYN Packet field. The default size in bytes is `64` and the maximum allowable value is `9216`.	Yes
TCP Window Size	The TCP window size in packets is above the maximum size. To tune this setting, change the setting at DoS Setup > Global , in the Too Low TCP Window Size field.	Yes
TIDCMP	ICMP source quench attack	Yes
Too Many Extension Headers	For an IPv6 address, the extension headers exceed the limit set at DoS Setup > Global , in the Too Many IPv6 Extension Header field.	Yes
TTL <= <tunable>	An IP packet with a destination that is not multicast has a TTL greater than 0 and less than the value set at DoS Setup > Global , in the IPv4 Low TTL field. The range for this setting is `1-4`.	Yes
UDP Flood	UDP flood attack	Yes
Unknown Option Type	Unknown IP option type.	No
Unknown TCP Option Type	Unknown TCP option type.	Yes

DNS attack vectors

Vector	Information	Hardware accelerated
DNS A Query	UDP packet, DNS Qtype is A_QRY, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS AAAA Query	UDP packet, DNS Qtype is AAAA, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS AXFR Query	UDP packet, DNS Qtype is AXFR, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS Any Query	UDP packet, DNS Qtype is ANY_QRY, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS CNAME Query	UDP DNS query, DNS Qtype is CNAME, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS IXFR Query	UDP DNS query, DNS Qtype is IXFR, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS MX Query	UDP DNS query, DNS Qtype is MX, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS Malformed	Malformed DNS packet	Yes
DNS NS Query	UDP DNS query, DNS Qtype is NS, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS NXDOMAIN Query	DNS query. Queried domain name does not exist.	Yes
DNS OTHER Query	UDP DNS query, DNS Qtype is OTHER, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS Oversize	Detects oversized DNS headers. To tune this value, set the Too Large DNS Packet setting at DoS Setup > Global to the maximum value for a DNS header, from `256-8192` bytes.	Yes
DNS PTR Query	UDP DNS query, DNS Qtype is PTR, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS Question Items != 1	UDP packet, DNS qdcount neq 1, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS Response Flood	UDP DNS Port=53, packet and DNS header flags bit 15 is 1 (response), VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS SOA Query	UDP packet, DNS Qtype is SOA_QRY, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS SRV Query	UDP packet, DNS Qtype is SRV, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes
DNS TXT Query	UDP packet, DNS Qtype is TXT, VLAN is <tunable>. To tune this value, set the DNS VLAN setting at DoS Setup > Global to the DNS VLAN (`0-4094`).	Yes

SIP attack vectors

Vector	Information	Hardware accelerated
SIP ACK Method	SIP ACK packets	Yes
SIP BYE Method	SIP BYE packets	Yes
SIP CANCEL Method	SIP CANCEL packets	Yes
SIP INVITE Method	SIP INVITE packets	Yes
SIP Malformed	Malformed SIP packets	Yes
SIP MESSAGE Method	SIP MESSAGE packets	Yes
SIP NOTIFY Method	SIP NOTIFY packets	Yes
SIP OPTIONS Method	SIP NOTIFY packets	Yes
SIP OTHER Method	Other SIP method packets	Yes
SIP PRACK Method	SIP PRACK packets	Yes
SIP PUBLISH Method	SIP PUBLISH packets	Yes
SIP REGISTER Method	SIP REGISTER packets	Yes
SIP SUBSCRIBE Method	SIP SUBSCRIBE packets	Yes
SIP URI Limit	The SIP URI exceeds the limit set at Dos Setup > Global , in the Too Long SIP URI field. This setting should be less than `1024`, the maximum length for a SIP URI in bytes.	Yes

Behavioral

Behavioral DDoS protection is enabled, by default, and all thresholds and threshold actions are applied. You can initiate leaning or relearning of dynamic signatures, adjust mitigation sensitivity, and enable redirection and scrubbing of IP addresses identified by the dynamic signatures. You also have the option of selecting Learn Only to track dynamic vector statistics, without enforcing any thresholds or limits.

In the case of an attack, the system dynamically creates signatures that characterize the attack. During the attack, you see them listed as behavioral vectors (starting with Sig). They are removed when the attack is over.