Forum Discussion

ZhangFan's avatar
ZhangFan
Icon for Nimbostratus rankNimbostratus
Nov 07, 2024

TCP Out-of-order, TCP Dup ACK, and TCP Retransmission packets are displayed.

I'd like to ask for advice，The LTM sends a TCP probe to the real server, and TCP Out-of-order, TCP Dup ACK, and TCP Retransmission packets are displayed. And at the same time, the LTM view log shows ...
application delivery
zamroni777's avatar
zamroni777
Icon for Nacreous rankNacreous

if havent, you can try disable ACK on PUSH which is default to Enabled.
https://my.f5.com/manage/s/article/K29377715#datatransfer

when enabled, vserver will wait for server response for Acknowledging client's TCP PUSH (which contained client request payload).
if server response time is slow, clients will do retransmissions.

you will have to solve the failed monitor separately.
it is better to consult with application team to set proper health monitor.

 

 

ZhangFan's avatar
ZhangFan
Icon for Nimbostratus rankNimbostratus
Nov 13, 2024

Thank you for your help.The result of the investigation is that the real server cannot respond to LTM health check probe packets.