RHEL5/CentOS5 KS Network Oddities (ifcfg-* gets re-written)

[Steve Robson]

> Subject: RHEL5/CentOS5 KS Network Oddities (ifcfg-* gets re-written)
> From: "kslist" <kslist at devo.com>
> Date: Wed, 26 Sep 2007 01:02:53 +0200 (CEST)
> To: kickstart-list at redhat.com
> 
> Hello KSers,
> 
> I am using my Kickstart script that I have adapted from RHEL 2.1, 3, and 4
> now on CentOS 5. CentOS 5 behaves differently when it comes to network
> configuration.
> 
> In essence: AFTER the successfull installation, during the first startup
> of the OS, something desctroys my network configuration. Specifically, the
> files that I have directly written in my %post script:
> /etc/sysconfig/network
> /etc/sysconfig/network-scripts/ifcfg-eth0
> /etc/sysconfig/network-scripts/ifcfg-eth1
> /etc/hosts
> /etc/resolve.conf
> are modified, and in the case of the ifcfg-* scripts, my scripts are moved
> to a *.bak file (which have a datestamp later than the files I created via
> %post, and which correspond to the firstboot) and a completely newfile is
> created in its place.
> 
> The network configuration that replaces my own is one for DHCP.
> 
> My guess is that this is a result of a change in behaviour of the
> "network" option. To quote from the RHEL 5 Installation Guide:
> 
> "Configures network information for the system. If the kickstart
> installation does not require networking (in other words, it is not
> installed over NFS, HTTP, or FTP), networking is not configured for the
> system. If the installation does require networking and network
> information is not provided in the kickstart file, the installation
> program assumes that the installation should be done over eth0 via a
> dynamic IP address (BOOTP/DHCP), and configures the final, installed
> system to determine its IP address dynamically. The network option
> configures networking information for kickstart installations via a
> network as well as for the installed system."
> 
> Now, I see a problem here:
> - I use DHCP to install the system (via Kickstart)
> - I however do NOT want to run the subsequently installed OS to use DHCP.
> 
> I would say that is a very very normal thing to want.

Completely normal, I do it all the time!

Typically I use one of the following "network" directives, depending how 
I want the resulting client to behave.  Beware that if you choose to 
statically address the target client using this method, its IP address 
must be on the same subnet as your KS server.

network --device=eth0 --bootproto=dhcp --hostname=lnx-blah
or
network --bootproto static --device=eth0 --gateway=I.P.of.GW 
--ip=I.P.of.client --nameserver=IP.of.DNS.server 
--netmask=I.P.of.netmask --onboot=on --hostname=lnx-blah

Hope this helps, see here for full detail: 
http://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/Installation_Guide-en-US/s1-kickstart2-options.html

-- 
   Regards,
   Steve

IT Support - UNIX/Linux                        Cadence Design Systems
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