Symptoms

TCP traffic from a FTP monitor intermittently picks the wrong source address for the egress interface if the pool member being monitored is located on a network served by ECMP routes. This causes FTP monitor to report false failures.

Impact

FTP monitors may intermittently report available pool member(s) as not available in a false failure.

Conditions

FTP monitor is configured to monitor pool members that are accessible through ECMP routes from the BIG-IP.

Workaround

Allow asymmetric routing by disabling VLAN keyed connections - 'tmsh modify sys db connection.vlankeyed value Disable'

Fix Information

Monitors now send traffic using the correct source address for the egress interface and do not falsely mark available pool members as down.

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips