[Pkg-utopia-maintainers] Bug#418023: Interfaces managed by
NetworkManager have MTU 576
daenzer at debian.org
Tue Apr 17 07:36:08 UTC 2007
On Mon, 2007-04-16 at 15:01 +0200, Michael Biebl wrote:
> Michel Dänzer wrote:
> > Package: network-manager
> > Version: 0.6.4-7
> > Severity: important
> > 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.
> Hi Michel,
> do you have the same problem when you manage your devices with ifupdown?
No, the desktop machines which don't use NetworkManager set the MTU to
1500 by default.
> Basically, nm_system_get_mtu() returning 0, means that the system
> default is used and network-manager does not mess with it.
I understand that, but it doesn't seem to be handled quite correctly
> Is there an authoritive config file, where we could read the mtu
I don't know, but grep can't seem to find anything in /etc.
> Otherwise I would refrain from setting the MTU to any
> arbitrary fixed number.
Sure, I didn't (mean to) suggest that. I think the default MTU should be
determined the same way as without NetworkManager.
Earthling Michel Dänzer | http://tungstengraphics.com
Libre software enthusiast | Debian, X and DRI developer
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