topic RE: How to MSS adjustment for TCP applications ? in ExtremeSwitching (EXOS/Switch Engine)

How to MSS adjustment for TCP applications ?

Weda — Wed, 26 Jul 2017 14:12:00 GMT

I want to adjust-mss of an interface to 1390. How can I do it in EXOS 16.2.1.6?

RE: How to MSS adjustment for TCP applications ?

StephenW — Wed, 26 Jul 2017 18:12:00 GMT

You can change the MTU on our switches (default is 1500). Which includes the MAC, IP, TCP, vlan headers.

The below wiki page has a example calculation from MSS to MTU. Hope this helps

https://en.wikipedia.org/wiki/Maximum_segment_size

RE: How to MSS adjustment for TCP applications ?

Weda — Wed, 26 Jul 2017 18:12:00 GMT

I want to adjust mss to 1390 in order to have a symmetry with 2 WAN connections.
but I can set MTU as 1500. Below that, it is not allowed.

RE: How to MSS adjustment for TCP applications ?

StephenW — Wed, 26 Jul 2017 18:12:00 GMT

I would think the mss value would be set on the application. Our switch doesn't look into the payload to check the MMS(maximum segment size). We look at the MTU.

RE: How to MSS adjustment for TCP applications ?

Bin — Thu, 27 Jul 2017 05:16:00 GMT

Hello Weda,

Here is the reference about how EXOS MTU works.

Show size of MTU EXOS
https://community.extremenetworks.com/extreme/topics/show-size-of-mtu-exos

Hope it will help you.

Best regards,
Bin