Applies To:Show Versions
Using Shun with Layer 7 DoS
Overview: Using Shun with Layer 7 DoS
- You configure an L7 DoS profile and an IP intelligence policy, and then associate both with a virtual server, and
- You are using mitigations other than device ID or URL in the DoS profile.
- Proactive Bot Defense with CAPTCHA challenge
- Stress-based Detection with Request Blocking and Rate Limiting
- Heavy URL Protection set to automatic detection
About the DoS shun list
Shun List system variables
What It Specifies
Whether to use the shun list to block IP addresses.
The minimum percentage of good transactions per IP address (or else the system adds it to the shun list).
The minimum requests per second before the system can apply shun mitigation.
The time in seconds (from 1-1000) to keep the IP address on the shun list.
(tmos)# modify sys db dosl7d.shun_list value disable
Configuring DoS protection for applications
- On the Main tab, click.The Protection Profiles list screen opens.
- ClickCreate.The Create New DoS Profile screen opens.
- In theNamefield, type the name for the profile, then clickFinished.
- In the list of DoS profiles, click the name of the profile you just created, and click theApplication Securitytab.This is where you set up application-level DoS protection.
- In theGeneral Settings, forApplication Security, clickEditand select theEnabledcheck box.General settings that you can configure are displayed.
- To configureHeavy URL Protection, edit the setting for which URLs to include or exclude, or use automatic detection.Another task describes heavy URL protection in more detail.
- To set up DoS protection based on the country where a request originates, edit theGeolocationssetting, selecting countries to allow or disallow.
- Move the countries for which you want the system to block traffic during a DoS attack into theGeolocation Blacklist.
- Move the countries that you want the system to allow (unless the requests have other problems) into theGeolocation Whitelist.
- Use the Stress-based or TPS-based Detection settings to select appropriate mitigations by geolocation in theHow to detect attackers and which mitigation to usesettings.
- When done, clickClose.
- If you have written an iRule to specify how the system handles a DoS attack and recovers afterwards, enable theTrigger iRulesetting.
- To better protect an applications consisting of one page that dynamically loads new content, enableSingle Page Application.
- If your application uses many URLs, inURL Patterns, you can create logical sets of similar URLs with the varying part of the URL acting like a parameter. ClickNot Configuredand type one or more URL patterns, for example,/product/*.php.The system then looks at the URL patterns that combine several URLs into one and can more easily recognize DoS attacks, for example, on URLs that might be less frequently accessed by aggregating the statistics from other similar URLs.
- If you want to use performance acceleration, inPerformance acceleration, select the TCP fastL4 profile to use as the fast-path for acceleration.The profiles listed are those created in.
- ClickUpdateto save the DoS profile.
Using an IP Intelligence policy with L7 DoS
- On the Main tab, click.The IP Intelligence Policies screen opens.
- ClickCreateto create a new IP Intelligence policy.
- In theNamefield, type a name for the IP intelligence profile, such asip-intell-l7.
- Leave theDefault Actionlist set toDrop.
- ForBlacklist Matching Policy, specify the action for the application DoS category.
- ForBlacklist Category, selectapplication_denial_of_service.L7 DoS classifies bad IP addresses in the shun list asapplication_denial_of_serviceby default. Other categories are for use if you purchased an IPI subscription (or IP intelligence database). Refer to information on IP intelligence blocking.
- ForAction, selectDrop.
- ForLog Blacklist Category Matches, selectYes.
Associating a DoS
profile and IP intelligence policy with a virtual server
- On the Main tab, click.The Virtual Server List screen opens.
- Click the virtual server that you want to have DoS protection and use the shun list.
- On the menu bar, from the Security menu, choose Policies.
- To specify the shun list action for Layer 7 DoS, from theIP Intelligencelist, selectEnabled, and then, from thePolicylist, select the IP intelligence policy (for example,ip-intelligence) to associate with the virtual server.You can also apply one IP intelligence policy at the global level that applies to all virtual servers on the system ().
- To enable denial-of-service protection, from theDoS Protection Profilelist, selectEnabled, and then, from theProfilelist, select the DoS profile to associate with the virtual server.
- ClickUpdateto save the changes.
Result of using shun list with Layer 7 DoS
- A client is sending lots of traffic from one IP address to the web application.
- Layer 7 DoS first inspects the traffic even before it gets to Application Security Manager™.
- If the client is blocked more than 90% of the time and it is sending at least 10 requests per second, the client IP address is put on the shun list.
- Traffic from the IP address on the shun list is blocked at the IP level (Layer 3) for two minutes.
- After that, the IP address is removed from the shun list.
- Traffic from the IP address is allowed through to L7 DoS where it is inspected according to the protections in the DoS profile.
- If the traffic is successful more than 10% of the time, it is allowed and handled by L7 DoS. Otherwise, that IP address is added back onto the shun list.