No. I never experienced loss of networking in the Dom0. My guess is that your bridge interface isn't configured correctly. There's a bunch of good >documentation on how Xen uses the different network interfaces. http://wiki.xensource.com/xenwiki/XenNetworking helped me understand it better.
I have read that over a few times now, but it misses the real fundamental elements that I am trying to learn now. Finally, installing CentOS without modifying _any_ defaults then logging in and performing a #yum install xen works? Problem is I don't want such a large bloated install, I had hoped for a minimal install but I am yet to deduce why the networking issue crops up repeatedly unless I install the defaults?
Do you know why the virbr0 in my system gets an IP not on my subnet, I only have one dhcp server which is scoped inside my subnet, obviously!
Soo confused :)
jlc