How do I remove a bridge that has an IP address that was brought up manually and isn't in /etc/network/interfaces?
$ ifconfig br100 br100 Link encap:Ethernet HWaddr 00:00:00:00:00:00 inet addr:172.16.0.5 Bcast:172.16.0.255 Mask:255.255.255.0
Can't delete it:
# brctl delbr br100 bridge br100 is still up; can't delete it
Can't bring it down with ifdown:
# ifdown br100 ifdown: interface br100 not configured