PMTU - PathMTU Discovery
PROBLEM: Slow file transfers and backups with different servers There have been a couple of different issues that I have run into regarding MTU and PMTU. resolve the issue of the server only sending frames off net at only 590 bytes. I have also had this issue relate to disconnects, as the server with the wrong setting get so busy (due to the small packets) that it was not sending acks in a timely fashion. http://www.netheaven.com/pmtu.html Solution: recommended that the servers’ mtusize discovery bit be set to “1”, to prevent 576 bytes and use your full packet size. For Windows XP: From Microsoft: Key: Tcpip\Parameters Value Type: REG_DWORD - Boolean Valid Range: 0,1 (False, True) Default: 1 (True) Description: If you set this parameter to 1 (True), TCP tries to discover the Maximum Transmission Unit (MTU or largest packet size) over the path to a remote host. By discovering the Path MTU and limiting TCP segments to this size, TCP can eliminate fragmentation at routers along the path t...