Forum Discussion

Steve_87971's avatar
Steve_87971
Icon for Nimbostratus rankNimbostratus
Jul 03, 2012

Proxy Maximum Segment not working as expected

Hi all,     I'm running a web-facing (as opposed to internal) IIS / ASP application behind an HA pair of 3900's with 10.2.3. We'd like to use the F5s to squeeze every last drop of performance fr...
config
design
Steve_87971's avatar
Steve_87971
Icon for Nimbostratus rankNimbostratus
Jul 03, 2012
These are the first lines of the TCP dumps when my client downloaded the webpage from the POC server, with "Proxy Maximum Segment" enabled on the client TCP profile.

 

 

The server is 1.6.3.7, my workstation is 4.9.0.6. These IPs and some names has been changed to protect the incompetent:

 

 

[me@ltm3:Active] config tcpdump -ni VLAN_external dst host 1.6.3.7 and src host 4.9.0.6

 

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

 

listening on VLAN_external, link-type EN10MB (Ethernet), capture size 108 bytes 15:11:00.809566 IP 4.9.0.6.fj-hdnet > 1.6.3.7.http: S 1715574144:1715574144(0) win 65535 mss 1360,nop,nop,sackOK

 

 

[me@ltm3:Active] ~ tcpdump -ni VLAN_external src host 1.6.3.7

 

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

 

listening on VLAN_external, link-type EN10MB (Ethernet), capture size 108 bytes

 

15:11:00.809580 IP 1.6.3.7.http > 4.9.0.6.fj-hdnet: S 2543644914:2543644914(0) ack 1715574145 win 4080 mss 1460,sackOK,eol

 

 

 

It looks like the client is sending MSS of 1360 yet the server is responding with 1460.