Description of problem:

If we define the option SRCADDR in the default route interface and we use xen, the script network-bridge does not create the default xen bridge xenbrX.

Version-Release number of selected component (if applicable):

 - xen-3.0.3-64.el5_2.3

How reproducible:

Always

Steps to Reproduce:
1. Define the option SRCADDR in the default route interface
2. Run /etc/xen/scripts/network-bridge start
3. We will get an error
  
Actual results:

network-bridge does not create the default xen bridge

Expected results:

network-bridge should create the default xen bridge xenbr0

Additional info:

The problem is the way the network-bridge script tries to find the vifnum to use. It uses:

vifnum=${vifnum:-$(ip route list | awk '/^default / { print $NF }' | sed 's/^[^0
-9]*//')}

This works if we don't have the SRCADDR, because the normal output for 'ip route list | grep /^default/' is:

default via 88.2.XX.XX dev eth1.11

So the dev is the last field, but if we use the SRCADDR option, the output is:

default via 88.2.XX.XX dev eth1.11  src 88.2.XX.ZZ

So it tries to use 88.2.XX.ZZ as the vifnum

A very simple fix is to define the vifnum in the /etc/xen/xend-config.sxp file:

(network-script 'network-bridge vifnum=0')

But I guess it would be nice to have that fixed so people does not waste time trying to make it work