In this somehow weekly series of posts I summarize noteworthy problems I encountered during my work week and how I solved them.

This week I tried to set up a fully automated installation for Centos 5.3 and ran into some problems.

Connect from Ubuntu 9.04 to Centos 5.3 via ssh

Connecting to a Centos 5.3 host using the installation of ssh provided by Ubuntu 9.04 should be straightforward. Unfortunally it doesn´t work out of the box because the connection seems to hang forever and times out in the end. The reason is that the sshd configuration option GSSAPIAuthentication is set to “on” by default on Centos hosts. This leads sshd to do DNS reverse lookups to Kerberos servers. If you don´t understand anything of this you can safely change the option to “no” on the Centos host and restart sshd. The problem should have went away by then. That´s it.

Mistake in Centos/Redhat Configuration

One more no-brainer: There is a mistake inside the documenation on howto set up PXE/BOOTP on RedHat/Centos. While the documentation states

allow booting; allow bootp; class
"pxeclients" { match if substring(option vendor-class-identifier, 0, 9)
= "PXEClient"; next-server <server-ip>; filename "linux-install/pxelinux.0"; }

the bold part must be /linux-install/pxelinux.0 (Mind the leading "/"). That´s it.

X11Forwarding on Centos

My Centos installation was based on an out of the box non-GUI profile. As I needed to run one of the X11-based system-config-* tools I used X11Forwarding. Unfortunally that didn´t work. All I got was

Can´t open display:

I found this bug report which asks one to install the package xorg-x11-xauth. That´s it.

Now it´s weekend. (Not really)