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During the course of a prolonged mail server performance issue we determined that we needed to make sure the mail server was sending smaller packets to get the best performance. We manually reduced the MSS setting on the server to 1380 but I am seeing in the 3 way handshake that the server is advertising MSS = 1340.

Thanks, Steve

asked 24 Jan '14, 15:10

skrall1965's gravatar image

accept rate: 0%

Did you actually configure the MSS on the server, or was it the MTU? The difference between the two values you listed is 40 bytes, and that's usually the difference between MTU and MSS. The MSS is usually the MTU minus 20 bytes for the IP headers and 20 bytes for the TCP headers.

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answered 24 Jan '14, 15:30

Jim%20Aragon's gravatar image

Jim Aragon
accept rate: 24%

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question asked: 24 Jan '14, 15:10

question was seen: 1,463 times

last updated: 24 Jan '14, 15:30

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