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