Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

Forum Discussion

ricky_paulus_gi's avatar
ricky_paulus_gi
Icon for Nimbostratus rankNimbostratus
Mar 05, 2017

TCP RETRANSMISSION IN F5

Hi Everyone,   I'm having trouble with TCP RETRANSMISSION in F5. I tried to send packet through F5. I have 3 PC's, each PC send   225.000 transactions. I have 675.000 transactions. when I see...
application delivery
big-ip
LTM
Leonardo_Souza's avatar
Leonardo_Souza
Icon for Cirrocumulus rankCirrocumulus
Mar 06, 2017

Not sure if this would be anything at the F5 level. A retransmission can occur if the network was busy, if there are interfaces errors, or other many factors.

I would start checking the interfaces errors and drops, in all devices. In F5 you can run this command:

tmsh show net interface all-properties

You can also play with the TCP profiles, there are profiles for LAN and WAN. Also, there some new TCP profiles in v13.