Re: Bridge stays down until a port is added

On Thu, 11 Aug 2011, Marc Haber wrote:

On Thu, Aug 11, 2011 at 08:17:06AM -0700, Stephen Hemminger wrote:

quoted

On Thu, 11 Aug 2011 09:06:59 +0200
Marc Haber [off-list ref] wrote:

quoted

Is that a feature? If so, why does the interface stay pingable after
removing the dummy0 interface from the bridge?

Yes, there are no links to send a packet so it seems logical
that there would be no carrier.

Yes, but if I can configure an IP address to the bridge I would expect
it to be reachable even if there are no interfaces in the bridge.
"Older" kernels used to behave like that.

For me (using kernel 3.0.0) it seems to work as I expect it:

aurora:~# brctl addbr br0
aurora:~# ifconfig br0 192.168.254.1 netmask 255.255.255.0 up
aurora:~# ping 192.168.254.1
PING 192.168.254.1 (192.168.254.1) 56(84) bytes of data.
64 bytes from 192.168.254.1: icmp_req=1 ttl=64 time=0.087 ms

aurora:~# ifconfig br0
br0       Link encap:Ethernet  HWaddr 96:e1:ba:9f:91:f9  
          inet addr:192.168.254.1  Bcast:192.168.254.255  Mask:255.255.255.0
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

The br0 interface has no carrier / is not "running", exactly like an 
ethernet port without a cable.

c'ya
sven-haegar

-- 
Three may keep a secret, if two of them are dead.
- Ben F.