On Fri, Apr 06, 2007 at 12:38:34PM +0200, Michel Dänzer wrote: > I noticed that all interfaces managed by NetworkManager seem to > have an MTU of 576 bytes (the minimum). This seems to have a negative > effect on download speed, or certainly not a positive one. As > nm_system_get_mtu() in src/backends/NetworkManagerDebian.c returns 0, > NetworkManager doesn't seem to set the MTU explicitly though, so I'm not > sure where the default is coming from. I verified that hacking the above > function to return 1500 results in interfaces managed by NetworkManager > having an MTU of 1500, with a line like > > Apr 6 12:18:52 thor NetworkManager: <information>^ISetting MTU of > interface 'sungem' to 1500 in syslog.
I've personally never seen this behaviour. I've also got a powerbook with a sungem network card and network-manager keeps it nicely at mtu 1500. When nm_system_get_mtu() returns 0, NM should just leave the mtu at the default value.. Looking at the code, if the configured mtu == 0, the set_mtu function just exits. So that all seems fine. So it seems we have ourselves a little mystery here :) I noticed your running kernel 2.6.21-rc5, could you try debian's 2.6.20-1 kernel to see if that changes the behaviour ? I know that that works fine on my powerpc with a sungem, so it allows us to easily see if the .21-rc kernel is doing strange things. Sjoerd -- "In order to make an apple pie from scratch, you must first create the universe." -- Carl Sagan, Cosmos