DHCP RH-linux-client, windows-server, DNS-registration not happening

armadilloman · 07-21-2004, 05:09 PM

Hello all,

The situation is as follows. There is a Windows 2003 server running the Microsoft DHCP server giving ip addresses to DHCP clients on the network. One of these clients is a Windows XP Pro box (WXPB). Another computer on the same subnet is a linux (RH7.3) box using

Code:

dhcpcd

for the DHCP client (RH7.3 has only one NIC, non-wireless, ethernet, device name eth0).

When I bring up a command window on WXBP and use

Code:

nslookup

on the ipaddress revealed from using the

Code:

ipconfig

command, I get a hostname back that corresponds to something expected. From the same window, if I issue an

Code:

nslookup

on the ip address given to RH7.3 (revealed from using the

Code:

ifconfig eth0

command), I get an error saying that the DNS server can not find that ip address, the reason being a non-existent domain.

WXPB has an ipaddress of 129.218.57.89
RH7.3 has an ipaddress of 129.218.57.98

From WXPB, I can access RH7.3 using ssh/telnet/ftp etc using RH7.3's ipaddress. However, I can not reach it using the hostname given in

Code:

/etc/resolv.conf

, which is of course overwritten each time dhcpcd gets new information.

According to the network administrator, the Windows machines update their own DNS entries. That is, they request an ipaddress from the DHCP machine, then apply their hostname to it and send it off to the DNS server. I checked on some Microsoft documents and this appears to be some kind of option that can be sent to the MS DHCP server (option 81). In my reading of man pages for dhcpcd and so forth, I have not found any way to do this.

Does anyone know how to get linux DHCP clients to work with the Windows DHCP server and then magically register it's own hostname with the DNS server?

I'm completely lost with this and I can't get samba to work with out the entry in DNS.

Thanks for the help.

idaho · 07-22-2004, 01:22 AM

Try entering the following in /etc/sysconfig/network

DHCP_HOSTNAME="RH73hostname"

where RH73hostname is the hostname of your RH7.3 box.

The RH network GUI config tool, neat, also has a place where you can set this.

armadilloman · 07-22-2004, 08:15 AM

Yeah, I saw this late yesterday on a different forum.

In /etc/sysconfig/network-scripts/ifcfg-eth0, I added the following:

Code:

DHCPCDARGS = -D
DHCP_HOSTNAME = hostname

Then I found that after I stop and restart the network service (/etc/rc.d/init.d/network stop|start), I had to use 'hostname' to set the hostname after that because it wasn't automatically set. Anyway to get around that?

Thanks for the tip!

idaho · 07-22-2004, 11:02 AM

In /etc/sysconfig/network you need an entry:
HOSTNAME="RH73hostname"

netsecwork · 06-23-2008, 01:51 PM

Hi, I am having the same issue. I was reading this post. Did it work?
Have you got it fixed?

Thanks
NSW

Quote:

Originally Posted by idaho

In /etc/sysconfig/network you need an entry:
HOSTNAME="RH73hostname"

a-wolfe · 01-12-2009, 08:53 AM

All you should need to configure is the hostname for an interface as DHCP_HOSTNAME=hostname in the /etc/sysconfig/network-scripts/ifcfg-eth0 configuration file.

I don't understand where the DHCPARGS=-D is coming from. I look at the man pages on RHEL5 for dhcpd and dhclient. There is seemingly no "-D" option to feed it.

Anyway this works with a M$ DNS/DHCP to get the hostname to register when an IP address is assigned by DHCP. We have more than one domain, though our "winders wonders" can only handle a single domain in the search path in /etc/resolv.conf. The main domain apparently can't be configured to search other domains at the DNS server. We have to maintain /etc/resolv.conf ourselves and include PEERDNS=no in the /etc/sysconfig/network configuration file.