Cisco ASA 5510 MSS Issue

I have a Cisco ASA 5510 appliance at my corporate office and cisco

1811's at our branch sites. I am troubleshooting some connectivity issues with a new Exchange server on the network. Troubleshooting as led me to think that the problem is a fragmentation issue on the network. When I started looking at the router configs ( 1811 ) i noticed that the previous network admin had set the default mss size to 1300, however no one could tell me why this had been done. I have heard of this being done to resolve some web browsing errors, but I have removed the setting and no one is complaining. Since removing the mss setting on the 1811's I can now send a test ping with don't fragment flag and a size of 1442 from all branch sites into the corporate router. This a substantial increase from before when the size was being limited to 1300 or less. However going out from corp the largest packet I can send is 1250. I have checked and rechecked the ASA config file and can find no setting to lower the mss or mtu size.

Anyone have any thoughts ?

Thanks

Reply to
dangentile
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i added the following to my asa

Then on my branch routers I added

ip tcp mss 1380 ( to match with the ASA )

This has helped, I am able to send ping x.x.x.x -f -l 1414 around to all sites now. However, I am still having a problem with exchange. Users running outlook constantly see messages that the connection to the server has been lost and restored all day long. Corp office ( exchange is part of local subnet here ) do not see the message. My research on this problem led us to think that it was a problem with fragmentation on the network this the original post. Any one have any thoughts now, or run into anything similar ?

Thanks

Reply to
dangentile

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