MTU problem

[Neil Watson]

I have a Linux host that uses pppoe for an Internet connection.  The
interface ppp0 has a MTU of 1482.

The same host also has some KMV guests attached to a bridge.  They get
their IP's from a DHCP server on this host.  By default guest interfaces
are set to an MTU of 1500.  This leads slow or none working connections
out to the internet.  If I manually set the MTU to below ppp0 (1472)
networking works normally.  I did set the DHCP service to give out the
1472 MTU setting to clients.

Now I'm trying to build more Debian guests.  It seems that the Debian
installer used the DHCP client but ignores the MTU setting.  The
interface is set to MTU 1500.  This seemingly cause the download portion
of the install to fail.

Is there a better way to go about this? Have I used the wrong settings
on DHCP?

#
# Sample configuration file for ISC dhcpd for Debian
#
# $Id: dhcpd.conf,v 1.4.2.2 2002/07/10 03:50:33 peloy Exp $
#

# option definitions common to all supported networks...
option domain-name "watson-wilson.ca";
option domain-name-servers 216.129.193.14, 216.129.193.130;

option subnet-mask 255.255.255.0;
option interface-mtu 1472;
default-lease-time 600;
max-lease-time 7200;

subnet 192.168.0.0 netmask 255.255.255.0 {
   range 192.168.0.2 192.168.0.20;
   option broadcast-address 192.168.0.255;
   option routers 192.168.0.1;
   option interface-mtu 1472;
}

host pluto{
   hardware ethernet 00:22:15:71:3c:ee; 
   fixed-address 192.168.0.10;
}

host print0{
     hardware ethernet 00:21:b7:a0:13:c8;
     fixed-address  192.168.0.19;
}

-- 
Neil Watson
Linux/UNIX Consultant
http://watson-wilson.ca
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists