Intermediate ASA-5525 breaks communication after 3-way handshake, Why?

MicJameson1 — Thu, 09 Feb 2023 15:44:55 GMT

Please view attached image. (**undocumented is that a Nexus 9k lives between the ASA and the "server".)

1. What might be the cause of the illustrated symptom?

2. Could this symptom be caused by the MSS inconsistency =1380 outbound vs.1460 inbound?

3. Could this symptom be caused by some kind of deep packet inspection? If so, how can I determine that?

Maybe this is relevant (I'm reading it right now) --Cisco ASA TCP State Bypass | Blue Network Security (bluenetsec.com)

Thank you.

Re: Intermediate ASA-5525 breaks communication after 3-way handshake,

Aref Alsouqi — Thu, 09 Feb 2023 16:13:07 GMT

I don't believe TCP state bypass would be the case here because if that was the case the 3-way handshake wouldn't have been completed, I wrote that post btw 🙂 From the attached image it does seem that after the 3-way handshake is completed the client doesn't start to send data to the server.

topic Intermediate ASA-5525 breaks communication after 3-way handshake, Why? in Network Security

Intermediate ASA-5525 breaks communication after 3-way handshake, Why?

Re: Intermediate ASA-5525 breaks communication after 3-way handshake,