Conflicts and network boot

Bruno Gola brunogola at
Fri Mar 17 22:13:02 UTC 2006

Good night (here in Brazil) everyone :-)
I'm new to the mailing-list and to dhcpd, and i'm already having problems ;(

The situation is: iin my office we have a dhcp server (that i dont have
access to)  that controls all machines. But, i need to netboot some
machines. 'till yesterday i was able to do this using bootp, pxelinux and
tftp, but we have a new machine and this one cant use bootp for this task,
so i need to migrate my bootp server to dhcp (what i've already did). The
machine that was booting with the bootp server, now is booting with the dhcp
(wich i set up for allowing bootp requests) fine, but my new machine doesn't
boot. Take a look at this log:

Mar 17 18:24:40 dostoieviski dhcpd: DHCPDISCOVER from 00:0c:29:88:3d:eb via
eth0                    <--- this is my new machine trying
Mar 17 18:24:40 dostoieviski dhcpd: DHCPOFFER on to
00:0c:29:88:3d:eb via eth0     <---- this is my new dhcp server
Mar 17 18:24:42 dostoieviski dhcpd: DHCPREQUEST for ( from 00:0c:29:88:3d:eb via eth0: ignored (not
authoritative).                          is the
principal dhcp server

and look this (i've used snort to see)

03/17-18:24:40.198628 ->
(the machine sending a DHCPDISCOVER)
UDP TTL:20 TOS:0x0 ID:0 IpLen:20 DgmLen:576
Len: 548

03/17-18:24:40.202439 ->
(the old dhcp server replying)
UDP TTL:128 TOS:0x0 ID:4271 IpLen:20 DgmLen:376
Len: 348

03/17-18:24:40.210248 ->
(my new dhcp server)
UDP TTL:64 TOS:0x10 ID:0 IpLen:20 DgmLen:328
Len: 300

03/17-18:24:42.280418 ->
UDP TTL:20 TOS:0x0 ID:1 IpLen:20 DgmLen:576
Len: 548

03/17-18:24:42.281635 ->
UDP TTL:128 TOS:0x0 ID:4307 IpLen:20 DgmLen:395
Len: 367

I think the old dhcp server cant handle bootp stuff, so thats why my old
machine can boot, but my new machine uses dhcp, so the old server conflicts
with my new server and the client gets information from the old one.

my dhcpd.conf:

group {
        allow booting;
        allow bootp;

        option domain-name "";
        option routers;
        option subnet-mask;
        option domain-name-servers;

        filename "pxelinux.0";

        host tchekov {
                hardware ethernet 00:14:22:7A:7D:3C;

        host pushkin {
                hardware ethernet 00:12:3F:76:83:94;

        host testebgola {
                hardware ethernet 00:0C:29:88:3D:EB;

subnet netmask {


Does anyone knows anyway to solve this conflict?

Thanks and sorry my english =),
Bruno Fialho Marques Gola <brunogola at>
Cel: (11) 9294-5883

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