Bug ID 692970: Using UDP port 67 for purposes other than DHCP might cause TMM to crash

Last Modified: May 29, 2024

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

Known Affected Versions:
12.1.2, 12.1.3, 12.1.3.1, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3

Fixed In:
14.0.0, 13.1.0.4, 13.0.1, 12.1.3.2

Opened: Nov 06, 2017

Severity: 2-Critical

Symptoms

DHCP relay presumes that a flow found via lookup is always a server-side flow of type DHCP relay. Hence TMM can crash when DHCP relay makes a server connection if UDP port 67 is used for another purpose, in which case a wrong DHCP server flow could be selected.

Impact

TMM restart causes traffic interruption or failover.

Conditions

A UDP port 67 is configured for a purpose other than DHCP relay.

Workaround

Do not use UDP port 67 for other virtual servers, or configure a drop listener on certain VLANs that cannot avoid using UDP port 67.

Fix Information

TMM no longer crashes with DHCP flow validation.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips