[syslinux] pxe weirdness

James_Martin at ao.uscourts.gov James_Martin at ao.uscourts.gov
Tue Jul 1 09:51:12 PDT 2003

Thanks for the response, but the problem is the PXE client is never 
getting to the TFTP server because it has received 2 gateways from the 
DHCP server...

I'm using dhcrelay to send DHCP requests from my PXE client to our DHCP 
server. The problem is that the PXE client receives both the correct 
gateway as defined in the dhcpd.conf, but also receives the dhcp relay 
servers IP address as the gateway, in the order of "Dhcp relay ip" 
"correct gateway ip".  Of course this is screwing the second part of the 
PXE transaction, which is TFTP, because it has the wrong gateway address. 
I can't figure out how the dhcrelay ip is getting thrown into the dhcp 
reply and given to the PXE client-- that IP is not specified anywhere in 
the dhcpd.conf.  I have tried explicitly setting "option router" for the 
ml370 host as you can see below, and it still had no effect.  This is 
using dhcp3.0pl1.  The dhcrelay station only has one NIC, and I'm running 
with dhcrelay -d, which is my DHCP/TFTP server.  PXE boots 

fine with the seahawk host, and also, if I set up a separate host on the network, the ml370 host boots fine as well.  I'm stumped. 
I've included my dhcpd.conf below, any help would be appreciated.




allow booting;
allow bootp;

not authoritative;
option domain-name "uscourts.dcn";
option domain-name-servers,;
ddns-update-style ad-hoc;

subnet netmask {
option routers;
option subnet-mask;
option time-offset -5; # Eastern Standard Time
filename "pxelinux.0";

subnet netmask {
option routers;
option subnet-mask;
option time-offset -5; # Eastern Standard Time
filename "pxelinux.0";

host seahawk {
hardware ethernet 00:02:a5:42:2f:f7;


host ml370 {
hardware ethernet 00:0b:cd:22:83:47;
option routers;



James S. Martin, RHCE
Administrative Office of the United States Courts
Washington, DC
(202) 502-2394

Erwan Velu <erwan at mandrakesoft.com>
07/01/2003 04:56 AM

        To:     James_Martin at ao.uscourts.gov
        cc:     syslinux at zytor.com
        Subject:        Re: [syslinux] pxe weirdness

> I successfully get an IP address from my DHCP server, but the machine 
> fails when it attempts to make it's TFTP connection with:
> "PXE-E32 - TFTP Open timeout"
> It never gets the pxelinux.0 file.
Your DHCP server must give the "next server" option to specify the TFTP
In dhcpd.conf, you must use for example:

# IP of you TFTP server

Then be sure that your tftp server is activated and running:
 cat /etc/xinetd.d/tftp | grep disable 
 service xinetd restart

Then some Broken PXE roms needs the blksize option:
In /etc/xinetd.d/tftp : server_args                              = -r 

Hope it will helps for your problem,
Erwan Velu
Linux Cluster Distribution Project Manager
43 rue d'aboukir 75002 Paris
Phone Number : +33 (0) 1 40 41 17 94
Fax Number   : +33 (0) 1 40 41 92 00
Web site     : http://www.mandrakesoft.com
OpenPGP key  : http://www.mandrakesecure.net/cks/

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