Bug ID 976853: SNAT pool traffic-group setting may override non-floating self IP's traffic-group

Last Modified: Apr 26, 2024

Affected Product(s):
BIG-IP TMOS(all modules)

Known Affected Versions:
14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 14.1.3.1, 14.1.4, 14.1.4.1, 14.1.4.2, 14.1.4.3, 14.1.4.4, 14.1.4.5, 14.1.4.6, 14.1.5, 14.1.5.1, 14.1.5.2, 14.1.5.3, 14.1.5.4, 14.1.5.6, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 16.0.1, 16.0.1.1, 16.0.1.2, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 17.0.0, 17.0.0.1, 17.0.0.2, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3

Opened: Dec 27, 2020

Severity: 3-Major

Symptoms

A non-floating self IP fails to respond to ARP on the standby system.

Impact

A standby device does not respond to ARP requests for floating IP addresses. If a SNAT is configured on the same IP as a non-floating self-ip on the standby, ARP responses will be disabled for that self-ip. Even after deleting the snat, or configuring it for another IP, ARP response for that self-ip will remain disabled. The effect of this will be that other IP devices will be unable to communicate with the self-ip after the ARP entry times out. For example: -- BIG-IP does not respond to ARP requests for the non-floating self-ip -- ConfigSync no longer working (if the affected self IP is the ConfigSync address) -- Health check traffic fails Note that simply deleting the SNAT translation will not restore service to the self-ip.

Conditions

An LTM SNAT translation address has been created which matches a non-floating self IP on the system, and the SNAT is configured in a floating traffic group.

Workaround

Delete the SNAT address, and then move the self-ip back to the non-floating traffic group, and disable and re-enable the arp setting. tmsh create ltm virtual-address <self-ip> arp enabled traffic-group traffic-group-local-only tmsh modify ltm virtual-address <self-ip> arp disabled tmsh delete ltm virtual-address <self-ip> Alternatively, after deleting SNAT translation, reboot the device (or restart tmm). When using this approach on multi-blade chassis devices, all blades need to be restarted.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips