This scenario combinessession continuity,multiple protocols (HTTP and FTP), andHA failover behavior, which directly implicatespersistence handling across devices and services.
Key Requirements Breakdown
Samepool member for entire session
Session must survivefailover
Session must spanmultiple services (HTTP and FTP)
Why Persistence Mirroring + Match Across Services Is Required
Persistence Mirroring
Ensurespersistence records are synchronizedfrom the active BIG-IP to the standby BIG-IP.
Without mirroring:
After failover, the standby device hasno persistence table
Clients are load-balanced again
Sessions break, forcing users to restart
Persistence mirroring is essential forsession continuity during failover
Match Across Services
Allows asingle persistence recordto be shared acrossmultiple virtual servers / protocols
Required when:
HTTP and FTP must use thesame pool member
Multiple services are part of a single application session
Together, these settings ensure:
Persistence survivesdevice failover
Persistence is honoredacross HTTP and FTP
Why the Other Options Are Incorrect
A. Cookie persistence and session timeoutCookie persistence only applies to HTTP and does not address FTP or failover synchronization.
B. Stateful failover and Network Failover detectionStateful failover applies toconnection state, notpersistence records, and does not link HTTP and FTP sessions.
D. SYN-cookie insertion threshold and connection low-water markThese are DoS / SYN flood protection settings, unrelated to persistence or HA behavior.
