How to send DHCP hostname with NM?

[Neal Becker]

How in the world do I get hostname set on a dhcp connection managed by NM?

In nm-applet, edit connections/Auto Ethernet shows
under IPv4 Setting
DHCP Client ID: (my name)

But it doesn't seem to send the hostname.

[Mogens Kjaer]

Neal Becker wrote:
> How in the world do I get hostname set on a dhcp connection managed by NM?

I have a

DHCP_HOSTNAME=evon800c

in the /etc/sysconfig/network-scripts/ifcfg-eth0 file,
and the DHCP server sees it:

Mar  9 12:22:39 server1 dhcpd: DHCPDISCOVER from 00:08:02:6c:20:ad via
bond0.20
Mar  9 12:22:40 server1 dhcpd: DHCPOFFER on 172.20.2.252 to
00:08:02:6c:20:ad (evon800c) via bond0.20
Mar  9 12:22:40 server1 dhcpd: DHCPREQUEST for 172.20.2.252 (172.20.0.1)
from 00:08:02:6c:20:ad (evon800c) via bond0.20
Mar  9 12:22:40 server1 dhcpd: DHCPACK on 172.20.2.252 to
00:08:02:6c:20:ad (evon800c) via bond0.20

Mogens

[Neal Becker]

Mogens Kjaer wrote:
> Neal Becker wrote:
> > How in the world do I get hostname set on a dhcp connection managed by
> > NM?
>
> I have a
>
> DHCP_HOSTNAME=evon800c
>
> in the /etc/sysconfig/network-scripts/ifcfg-eth0 file,
> and the DHCP server sees it:
>
> Mar  9 12:22:39 server1 dhcpd: DHCPDISCOVER from 00:08:02:6c:20:ad via
> bond0.20
> Mar  9 12:22:40 server1 dhcpd: DHCPOFFER on 172.20.2.252 to
> 00:08:02:6c:20:ad (evon800c) via bond0.20
> Mar  9 12:22:40 server1 dhcpd: DHCPREQUEST for 172.20.2.252 (172.20.0.1)
> from 00:08:02:6c:20:ad (evon800c) via bond0.20
> Mar  9 12:22:40 server1 dhcpd: DHCPACK on 172.20.2.252 to
> 00:08:02:6c:20:ad (evon800c) via bond0.20
>
> Mogens

Doesn't work here.  I have 
in /etc/sysconfig/network-scripts/ifcfg-eth1:

DHCP_HOSTNAME=nbecker6

Mar  3 07:38:26 localhost dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 
port 67 interval 8
Mar  3 07:38:26 localhost dhclient: DHCPOFFER from 10.32.111.2
Mar  3 07:38:26 localhost dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
port 67
Mar  3 07:38:26 localhost dhclient: DHCPACK from 10.32.111.2

Here is the entire file:
DEVICE=eth1
HWADDR=00:e0:81:b1:49:f8
ONBOOT=yes
DHCP_HOSTNAME=nbecker6
BOOTPROTO=dhcp
TYPE=Ethernet
USERCTL=no
PEERDNS=yes
IPV6INIT=no
NM_CONTROLLED=yes

[Mogens Kjaer]

Neal Becker wrote:
...
> Doesn't work here.  I have 
> in /etc/sysconfig/network-scripts/ifcfg-eth1:
>
> DHCP_HOSTNAME=nbecker6
>
> Mar  3 07:38:26 localhost dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 
> port 67 interval 8
> Mar  3 07:38:26 localhost dhclient: DHCPOFFER from 10.32.111.2
> Mar  3 07:38:26 localhost dhclient: DHCPREQUEST on eth1 to 255.255.255.255 
> port 67
> Mar  3 07:38:26 localhost dhclient: DHCPACK from 10.32.111.2

How does the log look on the server? My log files were from the server.

Mogens

[Neal Becker]

Mogens Kjaer wrote:
> Neal Becker wrote:
> ...
> > Doesn't work here.  I have
> > in /etc/sysconfig/network-scripts/ifcfg-eth1:
> >
> > DHCP_HOSTNAME=nbecker6
> >
> > Mar  3 07:38:26 localhost dhclient: DHCPDISCOVER on eth1 to
> > 255.255.255.255 port 67 interval 8
> > Mar  3 07:38:26 localhost dhclient: DHCPOFFER from 10.32.111.2
> > Mar  3 07:38:26 localhost dhclient: DHCPREQUEST on eth1 to
> > 255.255.255.255 port 67
> > Mar  3 07:38:26 localhost dhclient: DHCPACK from 10.32.111.2
>
> How does the log look on the server? My log files were from the server.
>
> Mogens

You mean dhcp server?  I have no access to that.

[Mogens Kjaer]

Neal Becker wrote:
...
> You mean dhcp server?  I have no access to that.

So how do you know that the hostname isn't sent to
the server?

Mogens

[Neal Becker]

Mogens Kjaer wrote:
> Neal Becker wrote:
> ...
> > You mean dhcp server?  I have no access to that.
>
> So how do you know that the hostname isn't sent to
> the server?
>
> Mogens

Because

host <blah> fails for this machine, but works for lots of others.

I think it's like this:
If you setup a new F10 box, and never play with any network setting or use 
NM, it works.  If you ever use NM, you're screwed.  I say this because the 
other machines that are working never had anyone login and mess with NM 
(these are all servers in a closet).

[Mogens Kjaer]

Neal Becker wrote:
...
> Because
>
> host <blah> fails for this machine, but works for lots of others.
>
> I think it's like this:

I've never had any problems like this. If the machine gets an IP
by DHCP, the server registers the hostname in DNS, independent of
the client machine running NM or not. If the hostname is specified
in DHCP_HOSTNAME.

Without access to the server's logfiles it would be difficult
to find out what your problem is...

Unless you can sniff the DHCP packets, or make a local setup
with your own DHCP server, not connected to the rest of the
network.

Mogens

[Neal Becker]

Mogens Kjaer wrote:
> Neal Becker wrote:
> ...
> > Because
> >
> > host <blah> fails for this machine, but works for lots of others.
> >
> > I think it's like this:
>
> I've never had any problems like this. If the machine gets an IP
> by DHCP, the server registers the hostname in DNS, independent of
> the client machine running NM or not. If the hostname is specified
> in DHCP_HOSTNAME.
>
> Without access to the server's logfiles it would be difficult
> to find out what your problem is...
>
> Unless you can sniff the DHCP packets, or make a local setup
> with your own DHCP server, not connected to the rest of the
> network.
>
> Mogens

I can say now for certain, that it will send the hostname iff you create 
/etc/dhclient-<iface>.conf with:
send host-name "<your hostname>";

[Mogens Kjaer]

Neal Becker wrote:
...
> I can say now for certain, that it will send the hostname iff you create 
> /etc/dhclient-<iface>.conf with:
> send host-name "<your hostname>";

This file do exist on my machines. It seems to be created automatically
by /etc/sysconfig/network-scripts/ifup-eth:

# cat dhclient-eth0.conf
send host-name "evon800c.crc.dk";  # temporary RHL ifup addition

Mogens