After upgrading from Hudson to Jenkins 1.397 with Tomcat 6.0.26 running on Red Hat Enterprise Linux Server release 5.5, Jenkins failed to start. The browser was stuck with the message:

Please wait while Jenkins is getting ready to work....

The tomcat log had the message:

Feb 15, 2011 11:49:41 AM javax.jmdns.impl.HostInfo newHostInfo
WARNING: Could not find any address beside the loopback.

The only interfaced configured in /etc/hosts is:

::1 localhost.localdomain localhost hostx

Looking at JmDNS, you can define the system property net.mdns.interface for JmDNS, I added the following system propery to my tomcat startup file and Jenkins successfully started:

-Dnet.mdns.interface=0.0.0.0