Bug ID 716851: SNMP EngineID type configuration for IPv4 and IPv6 address selection selects the loopback address

Last Modified: May 29, 2024

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

Known Affected Versions:
11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.1, 11.6.2, 11.6.3,,,,, 11.6.4, 11.6.5,,,, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2, 12.1.0, 12.1.1, 12.1.2, 12.1.3,,,,,,,, 12.1.4,, 12.1.5,,,, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,,,,,,, 13.1.1,,,,, 13.1.3,,,,,,, 13.1.4,, 13.1.5,, 14.0.0,,,,,, 14.0.1,

Fixed In:

Opened: Apr 25, 2018

Severity: 3-Major


TMSH commands allow you to enter parameters that are put into the snmpd.conf file for configuring the SNMP agent. If you specify an engineID, then it will be part of the system configuration that may synchronize as part of a failover group. That behavior may be undesirable, so instead, you can specify an engineIDType. Then each BIG-IP system makes its own engineID based upon type. Supported types are: -- IPv4 (1) -- IPv6 (2) -- MAC address (3) -- Text (4) Here is a sample tmsh command: tmsh modify sys snmp include "engineIDType 3" When the engineIDType is 1 or 2 (IPv4 address or IPv6 address), the BIG-IP system selects the localhost address which gives a non-unique engineID.


The engineID is not unique. This is especially a problem on vCMP.


Using engineIDType 1 or engineIDType 2 uses localhost address of or ::


Use engineIDType 3. Then the engineID is based on the MAC address, which is reliably unique.

Fix Information

In this release, the system determines the engineID in the following ways: -- The cluster IP address, if it is available, is used for a chassis. -- If there is no cluster address, then for IPv4, the eth0 or mgmt address is used. For IPv6 the first NIC's MAC address is used with fe80 in the first two bytes (this is the same logic that generates link-local addresses use). -- If you specify an engineIDNic as a variable in the snmpd.conf file, then that is the MAC address used.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips