Bug ID 1320889: Sock interface driver might fail to forward some packets.

Last Modified: May 29, 2024

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

Known Affected Versions:
14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,,,,, 14.1.5,,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8,,, 15.1.9,, 15.1.10,,,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,,,,, 16.1.4,,,, 17.1.0,,,

Fixed In:

Opened: Jul 14, 2023

Severity: 4-Minor


Sock interface driver might drop packets that require reassembly/re-segmentation on one side of the connection. For example, when client-side is configured with tcp-nagle and the server-side sends a stream of multiple small packets. This can increase latency on BIG-IP Virtual Edition on Azure when TSO/LRO is enabled. Drops can be monitored by running the following command: 'tmctl -d blade tmm/ndal_tx_stats -w 300' column 'drop_rej_dd'.


Some packets might never be forwarded by the BIG-IP system.


-- sock driver. (See K10142141) -- BIG-IP performing reassembly/re-segmentation on one side of the connection


In some cases disabling Nagle Algorithm in TCP profile to avoid reassembly/re-segmentation might improve the performance.

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips