By default,management-plane trafficuses themanagement routing table, whiledata-plane trafficuses theTMM routing table.

Remote Syslog traffic ismanagement-planetrafficunlessa management route exists.

If noManagement Routematches the Syslog server’s destination IP, the BIG-IP will instead:

UseTMM routes, and

Source the packets from aSelf IP

This is exactly what the administrator is observing.

To force Syslog traffic out the management port:

You must create aManagement Route, which is configured using:

tmsh create /sys management-route gateway network

This sends syslog traffic:

Out of themanagement interface

Using theManagement IPas the source

Thus,Option Bis correct.

Why the other options are incorrect:

A. Set the Management IP as the source address

Source address selection is overridden by routing.

Without a management route, traffic still goes out the data plane.

C. Create a new Self IP using a route domain

Unnecessary and not related to management-plane routing.

Syslog traffic should not rely on data-plane Self IPs.

D. Modify port lockdown on Self IP to allow UDP/514

This would allow Syslog trafficintothe BIG-IP over a Self IP, not forceoutboundtraffic via management.