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JC_WDN_334248's avatar
JC_WDN_334248
Icon for Nimbostratus rankNimbostratus
Sep 21, 2017

Corrupt TCP packet not dropped by F5

One of our customers connects to us through an F5. We had an recent incident where a packet had been corrupted in transit which was sent from our Cisco ASA to their F5 (we have packet captures from b...
application delivery
BIG-IP
security
Leonardo_Souza's avatar
Leonardo_Souza
Icon for Cirrocumulus rankCirrocumulus
Sep 25, 2017

Have a look in this solution:

 

https://support.f5.com/csp/article/K8082

 

If you are using a standard virtual server, yes, F5 must check the checksum. However, if you are using a virtual server with Fast L4 profile, I am not sure if it will calculate the checksum, as the handshake and TCP processing is done by the peers and not F5.

 

As you said the packet arrives in the F5 with bad checksum, so it can't be something F5 did.