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MSS value negotiated during ftp-data session establishment but wireshark shows larger blocks sent by server


As you can see at image during ftp-data session establishment size of MSS was negotiated equal to 1360 bytes. But then transfer started and server sends blocks much greater than MSS value, and greater than MTU (1500) value as well. Is there some missunderstanding of Wireshark output or how can be this justified?

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asked 26 May '15, 23:33

mongolio's gravatar image

accept rate: 0%

One Answer:


probably Large Segment Offload. Check the same session at the receiver, you then see the difference your NIC makes.

answered 27 May '15, 00:44

Jaap's gravatar image

Jaap ♦
accept rate: 14%