Bug ID 471073: When TMM is restarted, one or more HA connections may not be reestablished

Last Modified: Apr 10, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(all modules)

Known Affected Versions:
11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5

Fixed In:
11.6.0, 11.5.1 HF6

Opened: Jul 10, 2014
Severity: 2-Critical
Related AskF5 Article:
K15628

Symptoms

When TMM is restarted on the standby slot or on an HA peer, one or more HA connections may not be reestablished. This occurs based on which TMM is designated to make the outbound connection to the active peer; when mirroring across appliances, the connection may originate at either the active or standby peer.

Impact

If failover occurs in this state, some portion of the flows will not have been mirrored and will be reset.

Conditions

To determine if this is the case, use tmctl -f /var/tmstat/blade/tmm<n> ha_stat, for each of the tmm<n> files in /var/tmstat/blade/. If any of the selected connections is listed as 'none', then that TMM is not connected to the peer.

Workaround

Need to modify profile tcp _tcp4_ha_defaults in /usr/lib/tmm/tmm_base.tcl and add "syn_maxrtx 3" 1. mount /usr -o remount,rw 2. make copy of /usr/lib/tmm/tmm_base.tcl 3. In /usr/lib/tmm/tmm_base.tcl find profile tcp _tcp4_ha_defaults and add "syn_maxrtx 3" profile tcp _tcp4_ha_defaults { idle_timeout 30 keep_alive_interval 1 syn_maxrtx 3 maxrtx 4 rcvwnd 4194304 ... 4. Restart TMM. (traffic would be impacted if this is a active device) 5. mount /usr -o remount,ro This has to be done on both units. If there is more than one blade tmm_base.tcl has to be modified on all blades before restarting TMM.

Fix Information

Now, when TMM is restarted, all HA connections are reestablished.

Behavior Change