Manual Chapter : Configuring Remote High-Speed DNS Logging

Applies To:

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BIG-IP LTM

  • 14.0.1, 14.0.0

BIG-IP DNS

  • 14.0.1, 14.0.0
Manual Chapter

Configuring Remote High-Speed DNS Logging

Overview: Configuring remote high-speed DNS logging

You can configure the BIG-IP® system to log information about DNS traffic and send the log messages to remote high-speed log servers. You can choose to log either DNS queries or DNS responses, or both. In addition, you can configure the system to perform logging on DNS traffic differently for specific resources. For example, you can configure logging for a specific resource, and then disable and re-enable logging for the resource based on your network administration needs.
This illustration shows the association of the configuration objects for remote high-speed logging.
Association of remote high-speed logging configuration objects

About the configuration objects of remote high-speed DNS logging

When configuring remote high-speed DNS logging, it is helpful to understand the objects you need to create and why, as described here:
Object
Reason
Applies to
Pool of remote log servers
Create a pool of remote log servers to which the BIG-IP® system can send log messages.
Creating a pool of remote logging servers.
Destination (unformatted)
Create a log destination of Remote High-Speed Log type that specifies a pool of remote log servers.
Creating a remote high-speed log destination.
Destination (formatted)
If your remote log servers are the ArcSight, Splunk, IPFIX, or Remote Syslog type, create an additional log destination to format the logs in the required format and forward the logs to a remote high-speed log destination.
Creating a formatted remote high-speed log destination.
Publisher
Create a log publisher to send logs to a set of specified log destinations.
Creating a publisher.
DNS Logging profile
Create a custom DNS Logging profile to define the data you want the BIG-IP system to include in the DNS logs and associate a log publisher with the profile.
Creating a custom DNS logging profile for logging DNS queries. Creating a custom DNS logging profile for logging DNS responses. Creating a custom DNS logging profile for logging DNS queries and responses.
DNS profile
Create a custom DNS profile to enable DNS logging, and associate a DNS Logging profile with the DNS profile.
Creating a custom DNS profile to enable DNS logging.
LTM virtual server
Associate a custom DNS profile with a virtual server to define how the BIG-IP system logs the DNS traffic that the virtual server processes.
Configuring an LTM virtual server for DNS logging.

Creating a pool of remote logging servers

Before creating a pool of log servers, gather the IP addresses of the servers that you want to include in the pool. Ensure that the remote log servers are configured to listen to and receive log messages from the BIG-IP system.
Create a pool of remote log servers to which the BIG-IP system can send log messages.
  1. On the Main tab, click
    Local Traffic
    Pools
    .
    The Pool List screen opens.
  2. Click
    Create
    .
    The New Pool screen opens.
  3. In the
    Name
    field, type a unique name for the pool.
  4. Using the
    New Members
    setting, add the IP address for each remote logging server that you want to include in the pool:
    1. Type an IP address in the
      Address
      field, or select a node address from the
      Node List
      .
    2. Type a service number in the
      Service Port
      field, or select a service name from the list.
      Typical remote logging servers require port
      514
      .
    3. Click
      Add
      .
  5. Click
    Finished
    .

Creating a remote high-speed log destination

Before creating a remote high-speed log destination, ensure that at least one pool of remote log servers exists on the BIG-IP system.
Create a log destination of the
Remote High-Speed Log
type to specify that log messages are sent to a pool of remote log servers.
  1. On the Main tab, click
    System
    Logs
    Configuration
    Log Destinations
    .
    The Log Destinations screen opens.
  2. Click
    Create
    .
  3. In the
    Name
    field, type a unique, identifiable name for this destination.
  4. From the
    Type
    list, select
    Remote High-Speed Log
    .
    If you use log servers such as Remote Syslog, Splunk, or ArcSight, which require data be sent to the servers in a specific format, you must create an additional log destination of the required type, and associate it with a log destination of the
    Remote High-Speed Log
    type. With this configuration, the BIG-IP system can send data to the servers in the required format.
    The BIG-IP system is configured to send an unformatted string of text to the log servers.
  5. From the
    Pool Name
    list, select the pool of remote log servers to which you want the BIG-IP system to send log messages.
  6. From the
    Protocol
    list, select the protocol used by the high-speed logging pool members.
  7. Click
    Finished
    .

Creating a formatted remote high-speed log destination

Ensure that at least one remote high-speed log destination exists on the BIG-IP system.
Create a formatted logging destination to specify that log messages are sent to a pool of remote log servers, such as Remote Syslog, Splunk, or IPFIX servers.
  1. On the Main tab, click
    System
    Logs
    Configuration
    Log Destinations
    .
    The Log Destinations screen opens.
  2. Click
    Create
    .
  3. In the
    Name
    field, type a unique, identifiable name for this destination.
  4. From the
    Type
    list, select a formatted logging destination, such as
    Remote Syslog
    ,
    Splunk
    , or
    IPFIX
    .
    The Splunk format is a predefined format of key value pairs.
    The BIG-IP system is configured to send a formatted string of text to the log servers.
  5. If you selected
    Remote Syslog
    , then from the
    Syslog Format
    list select a format for the logs, and then from the
    High-Speed Log Destination
    list, select the destination that points to a pool of remote Syslog servers to which you want the BIG-IP system to send log messages.
    For logs coming from Access Policy Manager (APM), only the BSD Syslog format is supported.
  6. If you selected
    Splunk
    or
    IPFIX
    , then from the
    Forward To
    list, select the destination that points to a pool of high-speed log servers to which you want the BIG-IP system to send log messages.
  7. Click
    Finished
    .

Creating a publisher

Ensure that at least one destination associated with a pool of remote log servers exists on the BIG-IP system.
Create a publisher to specify where the BIG-IP system sends log messages for specific resources.
  1. On the Main tab, click
    System
    Logs
    Configuration
    Log Publishers
    .
    The Log Publishers screen opens.
  2. Click
    Create
    .
  3. In the
    Name
    field, type a unique, identifiable name for this publisher.
  4. For the
    Destinations
    setting, select a destination from the
    Available
    list, and click
    <<
    to move the destination to the
    Selected
    list.
    If you are using a formatted destination, select the destination that matches your log servers, such as Remote Syslog, Splunk, or ArcSight.
  5. Click
    Finished
    .

Creating a custom DNS logging profile for logging DNS queries

Create a custom DNS logging profile to log DNS queries, when you want to log only DNS queries.
  1. On the Main tab, click
    DNS
    Delivery
    Profiles
    Other
    DNS Logging
    or
    Local Traffic
    Profiles
    Other
    DNS Logging
    .
    The DNS Logging profile list screen opens.
  2. Click
    Create
    .
    The New DNS Logging profile screen opens.
  3. In the
    Name
    field, type a unique name for the profile.
  4. In the DNS Security area, from the
    Publisher
    list, select a destination to which the BIG-IP system sends DNS log entries.
  5. If you want the BIG-IP system to log all DNS queries, for the
    Log Queries
    setting, ensure that the
    Enabled
    check box is selected.
  6. If you want the BIG-IP system to include the query ID sent by the client in the log messages, for the
    Include Query ID
    setting, select the
    Enabled
    check box.
  7. Click
    Finished
    .
Assign this custom DNS logging profile to a custom DNS profile.

Creating a custom DNS logging profile for logging DNS responses

Create a custom DNS logging profile to log DNS responses when you want to determine how the BIG-IP system is responding to a given query.
  1. On the Main tab, click
    DNS
    Delivery
    Profiles
    Other
    DNS Logging
    or
    Local Traffic
    Profiles
    Other
    DNS Logging
    .
    The DNS Logging profile list screen opens.
  2. Click
    Create
    .
    The New DNS Logging profile screen opens.
  3. In the
    Name
    field, type a unique name for the profile.
  4. In the DNS Security area, from the
    Publisher
    list, select a destination to which the BIG-IP system sends DNS log entries.
  5. If you want the BIG-IP system to log all DNS responses, for the
    Log Responses
    setting, select the
    Enabled
    check box.
  6. If you want the BIG-IP system to include the query ID sent by the client in the log messages, for the
    Include Query ID
    setting, select the
    Enabled
    check box.
  7. Click
    Finished
    .
Assign this custom DNS logging profile to a custom DNS profile.

Creating a custom DNS logging profile for logging DNS queries and responses

Create a custom DNS logging profile to log both DNS queries and responses when troubleshooting a DDoS attack.
Logging both DNS queries and responses has an impact on the BIG-IP system performance.
  1. On the Main tab, click
    DNS
    Delivery
    Profiles
    Other
    DNS Logging
    or
    Local Traffic
    Profiles
    Other
    DNS Logging
    .
    The DNS Logging profile list screen opens.
  2. Click
    Create
    .
    The New DNS Logging profile screen opens.
  3. In the
    Name
    field, type a unique name for the profile.
  4. In the DNS Security area, from the
    Publisher
    list, select a destination to which the BIG-IP system sends DNS log entries.
  5. If you want the BIG-IP system to log all DNS queries, for the
    Log Queries
    setting, ensure that the
    Enabled
    check box is selected.
  6. If you want the BIG-IP system to log all DNS responses, for the
    Log Responses
    setting, select the
    Enabled
    check box.
  7. If you want the BIG-IP system to include the query ID sent by the client in the log messages, for the
    Include Query ID
    setting, select the
    Enabled
    check box.
  8. Click
    Finished
    .
Assign this custom DNS logging profile to a custom DNS profile.

Creating a custom DNS profile to enable DNS logging

Ensure that at least one custom DNS Logging profile exists on the BIG-IP system.
Create a custom DNS profile to log specific information about DNS traffic processed by the resources to which the DNS profile is assigned. Depending upon what information you want the BIG-IP system to log, attach a custom DNS Logging profile configured to log DNS queries, to log DNS responses, or to log both.
  1. On the Main tab, click
    DNS
    Delivery
    Profiles
    DNS
    .
    The DNS list screen opens.
  2. Click
    Create
    .
    The New DNS Profile screen opens.
  3. In the
    Name
    field, type a unique name for the profile.
  4. Select the
    Custom
    check box.
  5. In the Logging and Reporting area, from the
    Logging
    list, select
    Enabled
    .
  6. In the Logging and Reporting area, from the
    Profile
    list, select a custom DNS Logging profile.
  7. Click
    Finished
    .
You must assign this custom DNS profile to a resource before the BIG-IP system can log information about the DNS traffic handled by the resource.

Configuring a listener for DNS logging

Ensure that at least one custom DNS profile with logging configured exists on the BIG-IP system.
Assign a custom DNS profile to a listener when you want the BIG-IP system to log the DNS traffic the listener handles.
This task applies only to BIG-IPDNS-provisioned systems.
  1. On the Main tab, click
    DNS
    Delivery
    Listeners
    .
    The Listeners List screen opens.
  2. Click the name of the listener you want to modify.
  3. In the Service area, from the
    DNS Profile
    list, select a custom DNS profile that is associated with a DNS Logging profile.
  4. Click
    Update
    .

Configuring logs for global server load-balancing decisions

Ensure that at least one wide IP exists in the BIG-IP DNS configuration, and that high-speed remote logging is configured on the device.
When you want to view the global server load-balancing decisions made by BIG-IP DNS in the high-speed remote logs, configure the verbosity of the information that displays in the logs.
  1. On the Main tab, click
    DNS
    GSLB
    Wide IPs
    .
    The Wide IP List screen opens.
  2. Click the name of the wide IP you want to modify.
  3. From the General Properties list, select
    Advanced
    .
  4. For the
    Load-Balancing Decision Log
    setting, select the check boxes of the options that you want to include in the high-speed remote logs.
    Check-box option
    Log information
    Pool Selection
    The pool selected to answer a DNS request, and why the pool was selected.
    Pool Traversal
    The pools in the wide IP considered during the load-balancing decision, and why the pool was selected.
    Pool Member Selection
    The pool member selected to answer a DNS request, and why the member was selected.
    Pool Member Traversal
    The members of the pool considered during the load-balancing decision, and why the member was selected.
    Example log for a wide IP configured for Ratio load balancing when
    Load-Balancing Decision Log
    is set to only
    Pool Selection
    :
    2013-03-14 15:40:05 bigip1.com to 10.10.10.9#34824: [wip.test.net A] [ratio selected pool (pool_b) with the first highest ratio counter (1)]
    Example log for a wide IP configured for Ratio load balancing when
    Load-Balancing Decision Log
    is set to both
    Pool Selection
    and
    Pool Traversal
    :
    2013-03-14 16:18:41 bigip1.com from 10.10.10.9#35902 [wip.test.net A] [ratio selected pool (pool_a) - ratio counter (0) is higher] [ratio skipped pool (pool_b) - ratio counter (0) is not higher] [ratio reset IPv4 ratio counter to original ratios - the best had zero ratio count] [ratio selected pool (pool_a) - ratio counter (1) is not higher] [ratio selected pool (pool_b) - ratio counter (1) is not higher] [ratio selected pool (pool_a) with the first highest ratio counter (1)]

Disabling DNS logging

Disable DNS logging on a custom DNS profile when you no longer want the BIG-IP system to log information about the DNS traffic handled by the resources to which the profile is assigned.
You can disable and re-enable DNS logging for a specific resource based on your network administration needs.
  1. On the Main tab, click
    DNS
    Delivery
    Profiles
    DNS
    .
    The DNS profile list screen opens.
  2. Click the name of a profile.
  3. Select the
    Custom
    check box.
  4. In the Logging and Reporting area, from the
    Logging
    list, select
    Disabled
    .
  5. Click
    Update
    .
The system does not perform DNS logging on the DNS traffic handled by the resources to which this profile is assigned.