Scenario–1: High CPU usage on F5 LTM
Problem: The F5 LTM system is experiencing high CPU usage, resulting in slow performance and potential service disruptions.
Solution:
- Use the command “tmsh show sys resource” to check the CPU usage and identify the processes that are consuming high CPU. This command will show the CPU usage of each process running on the F5 LTM system.
- Use the command “tmsh show sys process [PID]” to check the details of the process that is consuming high CPU. This command will show the details of the process such as memory usage, status, and configuration.
- Check the configuration of the virtual servers, pools, and other components on the F5 LTM system to identify if there are any misconfigurations that may be causing high CPU usage.
- Check the network connectivity between the F5 LTM system and the pool members to ensure that the members are reachable and responding to traffic.
- If the issue is related to a specific virtual server, you can use the command “tmsh show ltm virtual [virtual_server_name]” to check the status and configuration of the virtual server.
- Once the cause of the high CPU usage is identified, take appropriate action to resolve the issue. This may include modifying the configuration, adding more resources to the system, or troubleshooting the specific process that is consuming high CPU.
Scenario-2: Connection timeouts on F5 LTM
- Problem: The F5 LTM system is experiencing connection timeouts, resulting in poor performance and potential service disruptions.
- Solution:
- Use the command “tmsh show ltm pool [pool_name]” to check the status of the pool and identify if any of the pool members are down. This command will show the status of each pool member, including the availability and connection status.
- Use the command “tmsh show ltm node [node_name]” to check the status and configuration of the nodes. This command will show the details of each node, including the IP address, status, and connection information.
- Check the network connectivity between the F5 LTM system and the pool members to ensure that the members are reachable and responding to traffic.
- If the issue is related to a specific virtual server, you can use the command “tmsh show ltm virtual [virtual_server_name]” to check the status and configuration of the virtual server.
- Check the configuration of the virtual server and pool to ensure that the correct settings are being used.
- Once the cause of the connection timeouts is identified, take appropriate action to resolve the issue. This may include modifying the configuration, troubleshooting the network connectivity, or adding more resources to the system.
Scenario-3: Traffic not being load balanced on F5 LTM
- Problem: The F5 LTM system is not distributing the traffic evenly among the pool members, resulting in poor performance and potential service disruptions.
- Solution:
- Use the command “tmsh show ltm pool [pool_name]” to check the status of the pool and identify if all pool members are active and available. This command will show the status of each pool member, including the availability and connection status.
- Use the command “tmsh show ltm virtual [virtual_server_name]” to check the status and configuration of the virtual server, including the load balancing method. This command will show the details of the virtual server, including the IP address, port, status, and load balancing method.
- Check the configuration of the pool and virtual server for any misconfigurations that may be causing the traffic not to be load balanced.
- Check the network connectivity between the F5 LTM system and the pool members to ensure that the members are reachable and responding to traffic.
- If the issue is related to a specific virtual server, you can use the command “tmsh show ltm virtual [virtual_server_name]” to check the status and configuration of the virtual server.
- Once the cause of the traffic not being load balanced is identified, take appropriate action to resolve the issue. This may include modifying the configuration, troubleshooting the network connectivity, or adding more resources to the system.
Scenario-4: Incorrect SSL certificate being presented on F5 LTM
- Problem: The F5 LTM system is presenting an incorrect SSL certificate to clients, resulting in certificate errors and potential security vulnerabilities.
- Solution:
- Use the command “tmsh show ltm virtual [virtual_server_name]” to check the status and configuration of the virtual server, including the SSL profile. This command will show the details of the virtual server, including the IP address, port, status, and SSL profile.
- Use the command “tmsh show ltm profile client-ssl [profile_name]” to check the SSL certificate and key being used by the profile. This command will show the details of the SSL profile, including the certificate and key being used.
- Check the configuration of the virtual server and SSL profile to ensure that the correct SSL certificate is being used.
- Use the command “tmsh install sys crypto key [key_name] from-local-file [path_to_key]” to install the correct SSL certificate and key.
- Modify the virtual server to use the correct SSL profile with the new certificate and key
- Test the virtual server to ensure that the correct certificate is being presented to clients
Scenario-5: Persistence not working on F5 LTM
- Problem: The F5 LTM system is not maintaining persistence for clients, resulting in poor performance and potential service disruptions.
- Solution:
- Use the command “tmsh show ltm virtual [virtual_server_name]” to check the status and configuration of the virtual server, including the persistence profile. This command will show the details of the virtual server, including the IP address, port, status, and persistence profile.
- Use the command “tmsh show ltm persistence persist-records” to check the persistence records. This command will show the details of all persistence records, including the type and status.
- Check the configuration of the virtual server and persistence profile to ensure that the correct persistence method is being used.
- Verify that the persistence is working by checking if the traffic is being sent to the same pool member after the first request.
- Use the command “tmsh modify ltm virtual [virtual_server_name] persistence [persistence_profile_name]” to modify the persistence profile and correct any misconfigurations.
- Test the virtual server to ensure that persistence is working as expected