DHCP server / PXE boot

freeindy · 03-03-2008, 10:32 AM

Hi,

I'm using the distro Centos 5.1 and want it to be have a dhcp server so that machines connected to it can nfs boot from it.

I have two ethernet cards:
eth0: gets an dhcp address from the outside world. It should not be conflicted with the other card regarding dhcp server.

Code:

eth0      Link encap:Ethernet  HWaddr 00:01:02:24:68:37  
          inet addr:172.25.2.68  Bcast:172.25.255.255  Mask:255.255.0.0
          inet6 addr: 2001:1:1234:0:201:2ff:fe24:6837/64 Scope:Global
          inet6 addr: fe80::201:2ff:fe24:6837/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:19196 errors:0 dropped:0 overruns:1 frame:0
          TX packets:6142 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:5662500 (5.4 MiB)  TX bytes:1115875 (1.0 MiB)
          Interrupt:9 Base address:0xc00

eth1 has the following setup:

Code:

eth1      Link encap:Ethernet  HWaddr 00:1B:21:0E:66:26  
          inet addr:192.168.0.254  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::21b:21ff:fe0e:6626/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:352 errors:0 dropped:0 overruns:0 frame:0
          TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:209088 (204.1 KiB)  TX bytes:4386 (4.2 KiB)
          Base address:0x6800 Memory:feda0000-fedc0000

And the route table looks like this:

Code:

192.168.0.0     *               255.255.255.0   U     0      0        0 eth1
172.25.0.0      *               255.255.0.0     U     0      0        0 eth0
169.254.0.0     *               255.255.0.0     U     0      0        0 eth1
default         192.168.0.1     0.0.0.0         UG    0      0        0 eth1
default         172.25.0.254    0.0.0.0         UG    0      0        0 eth0

The dhcpd.conf looks like this:

Code:

# dhcpd.conf
#
deny unknown-clients;
ddns-update-style none;
allow bootp;

subnet 192.168.0.0 netmask 255.255.255.0
{
  default-lease-time      1209600;        # two weeks
  max-lease-time          31557600;       # one year
  option routers 192.168.0.1;

  group
  {
    host cb6
    {
      hardware ethernet 00:a0:a5:5d:ad:81;
      fixed-address 192.168.0.6;

      # MVL installation image root
      option root-path
      "/opt/os_images/mv_cge_4.0.1/cge/devkit/x86/pentium4/target";

      filename "pxelinux.0";              # Relative to TFTP root
    }

    host cb9
    {
      hardware ethernet 00:a0:a5:5d:ad:ec;
      fixed-address 192.168.0.9;

      # MVL installation image root
      option root-path
      "/opt/os_images/mv_cge_4.0.1/cge/devkit/x86/pentium4/target";

      filename "pxelinux.0";              # Relative to TFTP root
    }
  }
}

Now, When I boot the target with the mac address to cb6 I get the following message in the /var/log/messages:

Code:

Mar  3 17:28:08 AccServer kernel: e1000: eth1: e1000_watchdog_task: NIC Link is Down
Mar  3 17:28:10 AccServer kernel: e1000: eth1: e1000_watchdog_task: NIC Link is Up 100 Mbps Full Duplex, Flow Control: RX/TX
Mar  3 17:28:15 AccServer dhcpd: DHCPDISCOVER from 00:a0:a5:5d:ad:81 via eth1: network 192.168.0.0/24: no free leases

Does anyone know why?

Thanks a million
Indy

harry edwards · 03-03-2008, 05:15 PM

I've found this:

Quote:

After adding my 2nd network card, I noticed dhcpd wasn't working anymore.

If more than one network card resides in the DHCP server, it is recommended to specify which interface(s) the DHCP server will use. Edit /etc/sysconfig/dhcpd by adding the appropriate interface to the DHCPDARGS= line. The entry in /etc/sysconfig/dhcpd should appear as follows:

DHCPDARGS=eth0

Also, here are several means for debugging dhcpd in no particular order:

* /usr/sbin/dhcpd -d -f
* tail -f /var/lib/dhcpd.leases
* tail -f /var/log/messages

freeindy · 03-04-2008, 02:31 AM

Thanks Harry,

That did the trick. Cheers.

Indy