F5CAB5: BIG-IP Administration Support and Troubleshooting

BIG-IP’s data plane, centered on TMM, performs runtime network-traffic processing and hosts SessionDB, which stores runtime data including APM/SWG user sessions. iControl transactions, MCPD transactions, and the Configuration utility are management or configuration functions associated with the control plane.

The virtual address has ARP disabled. ARP must be enabled for the BIG-IP system to respond to ARP requests for the virtual IP address on the local network; otherwise, clients cannot resolve that address and establish a connection. The virtual server and both pool members are available, so the pool is not shown as failed.

A black BIG-IP pool-member indicator denotes an administratively disabled member, meaning it has been forced offline. A health monitor failure marks a member down instead, which is represented separately as a red status.

A Gateway ICMP monitor succeeds only when it receives a response to an ICMP echo probe. A host-based firewall on the affected server can block ICMP echo requests or replies, so BIG-IP reports the monitored pool as down even when the server and its other services are active.

A trunk member interface is DOWN when its physical link to the peer device is unavailable. Trunks provide link failover when a member link becomes unavailable, and the peer switch connection supplies that physical link. Default routes do not affect link state, and media speed can be negotiated automatically.