301B: BIG-IP LTM Specialist: Maintain and TroubleshootDemo

By F5 · Question Mode

QuestionQ56

Troubleshoot Basic Virtual Server Connectivity Issues

A new VLAN, vlan301, has been configured on a highly available LTM device in partition ApplicationA. A newly directly connected backend server has been placed on vlan301. However, connectivity problems occur when pinging the default gateway. The VLAN self IPs configured on the LTM devices are 192.168.0.251 and 192.168.0.252, with floating IP 192.168.0.253. The LTM Specialist must perform a packet capture to help troubleshoot the connectivity.

Which command should the LTM Specialist run from the LTM device command-line interface to capture the attempted pings to the LTM device default gateway on VLAN vlan301?

  • A tcpdump -ni /ApplicationA/vlan301 'host 192.168.0.253'
  • B tcpdump -ni vlan301 'host 192.168.0.253'
  • C tcpdump -ni /ApplicationA/vlan301 'host 192.168.0.251 or host 192.168.0.252'
  • D tcpdump -ni vlan301 'host 192.168.0.251 or host 192.168.0.252'
Explanation

In a high-availability LTM configuration, the floating self IP is the shared gateway address used by directly connected hosts. Capturing on the fully qualified VLAN path /ApplicationA/vlan301 and filtering for host 192.168.0.253 captures the attempted gateway pings on that partition’s VLAN. F5 documentation shows that VLANs in application containers must be referenced by their full path when used with tcpdump.

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