Re: Changing MTU for pxeboot

[Ray Van Dolson <rvandolson esri com>]

On Fri, May 11, 2007 at 06:38:22PM +0200, Olivier BONHOMME wrote:
> Hello everybody,
> 
> I am trying to install a Fedora Core 6 using pxeboot. The problem is 
> that the server which contains the install images has a MTU set to 9000. 
> Then when I try to download the install image on the system which I try 
> to install, the transfer fails because I have a MTU 9000 on a side and a 
> MTU 1500 on the other side.
> 
> I saw on the Redhat bugzilla, that it was possible to send a new MTU 
> parameter to /sbin/loader and anaconda using the command line. I tried 
> to put mtu=9000 on my pxelinux.cfg file but it doesn't seem to work.
> 
> Does somebody has this problem and does somebody know how to change the 
> MTU parameter on /sbin/loader and anaconda in a automatically way ?
> 
> Thank you for your answers

Your card probably doesn't support an MTU size of 9000?

Is there an intermediary firewall that might be blocking the ICMP
fragmentation packets that should help with the MTU size?

Does anaconda let you set the MSS (maximum segment size)?

Can you run a tcpdump when the stalls occur to see if your machine is
sending back ICMP packet too large packets?

Ray