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Forum Discussion

Amartya_Ghosh_1's avatar
Amartya_Ghosh_1
Icon for Nimbostratus rankNimbostratus
Mar 10, 2014

TCP Window Scaling in F5 LTM 11.2

We are observing some weird behaviour on the traffic passing through LTM in one of our setup. While analyzing TCP captures we identified LTM is disabling windows scaling ( Negotiated scale factor 0x0...
application delivery
deployment
LTM
microsoft
performance
boneyard's avatar
boneyard
Icon for MVP rankMVP
Mar 16, 2014

sorry it took a little longer. it has been a while since i worked with this so i had to configure it to see how it worked.

 

it is the Send Buffer / Receive Buffer that "enables" window scaling. remember the bigip is a full proxy (at least on your standard virtual servers), so if its buffers are only 64k max then window scaling is not needed. so if you increase them the bigip will start doing window scaling to enable these larger buffers.

 

tcp-wan-optimized / tcp-lan-optimized play with different settings, but not with the actual Send / Receive buffer, so using them isnt enough.