SOLVED: Very strange hostname / DHCP issue

James Wells · n00b Joined: 10 Sep 2004 Posts: 57

Greetings,

I have recently begun having a strange problem on my laptop, when my system loses it's hostname entries after I start the wireless network.

To test this, I have run various combinations of hostname -a, hostname -f, etc. Before I bring up my wireless network, they all show the correct hostname and domainname combinations, however, after dhcp completes for my wireless device, all hostname entries fail. This causes various other things to fail my syslog-ng, kdeinit, sendmail, and a few others.

If I run /etc/init.d/hostname restart after dhcp completes for my wireless, everything works correctly, assuming that I haven't yet started any of the affected processes.

EDIT: I got around the issue by commenting out lines 135 - 146 in dhcp-3.0.5_beta1's /sbin/dhclient-script.

magic919 · Posted: Wed Aug 16, 2006 7:47 am Post subject:

It's worth sticking your FQDN in the hosts file if you haven't already.

James Wells · n00b Joined: 10 Sep 2004 Posts: 57

Yup. In my /etc/hosts file I have;
127.0.0.1 <MyLaptop FQDN> <MyLaptop> localhost.localdomain localhost

Something else I just noticed is that when I run DHCP at home, I get the same host as I have configured in my /etc/hosts so I have not issues there. Is there a way to tell dhcp not to set the hostname? I can see there is an option not to send the hostname, but I see nothing about not setting the hostname.

UberLord · Posted: Thu Aug 17, 2006 6:32 am Post subject:

Depends on which dhcp client you use. So which one is it?
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OldTango · l33t Joined: 21 Feb 2004 Posts: 718

I need some assistance getting my network working properly again after a world update.

I am using dhcpcd for eth0 on the server to get an IP form my ISP and using DHCP (via eth1) to assign IP's automatically to the machines on the lan which are using dhcpcd to get their IP's

When I reboot the server I get a message telling me I need to update my /etc/conf.d/net file because I am using old style syntax. After reading the net.example file and changing some settings I can get eth0 to come up and get and IP but still get this errror message. Eth0 now comes up and gets an IP (via DHCP). DHCP fails to run (no error message) and eth1 comes up but dosen't get an IP.

Before my clients on the lan can use the internet or connect to the server I have to manually run

UberLord · Posted: Thu Aug 17, 2006 3:01 pm Post subject:

Alas my crystal ball has broken, but I suspect you are getting that message as you're still trying to use an old var such as gateway or iface_eth0
_________________
Use dhcpcd for all your automated network configuration needs
Use dhcpcd-ui (GTK+/Qt) as your System Tray Network tool

magic919 · Posted: Thu Aug 17, 2006 3:02 pm Post subject:

Did someone remove the New Topic button??

James Wells · n00b Joined: 10 Sep 2004 Posts: 57

lbrtuk · l33t Joined: 08 May 2003 Posts: 910

From /etc/conf.d/net.example:

James Wells · n00b Joined: 10 Sep 2004 Posts: 57

The option you are showing, says to send or not to send the hostname to the DHCP server. As I understand it, that option has no effect if the dhcp server sends a pre-generated name. I should also point out that I already had the nosendhost option set and still had my hostname changed on me when I recieved a DHCP option host-name entry from the DHCP server. The only time it doesn't change is when I am at home where my DHCP server sends the hostname that my laptop uses ayway.

lbrtuk · l33t Joined: 08 May 2003 Posts: 910

I was more looking at the nodns entry. If the host settings your DHCP is sending you are breaking your connection, set nodns.