How to configure DHCP client on a bridge ?

[Brooks Davis]

On Fri, Mar 13, 2009 at 07:33:15AM +0100, Olivier Cochard-Labb? wrote:
> Hi,
> 
> I'm trying to follow the advice fount in the handbook by configuring
> the IP address on the bridge0 interface rather than on a member
> interface.
> Then I've configured my rc.conf like that:
> 
> cloned_interfaces="bridge0"
> ifconfig_bridge0="addm bge0 addm xl0 DHCP"
> ifconfig_bge0="up"
> ifconfig_xl0="up"
> 
> But, with this configuration, the dhclient didn't start automatically
> on the bridge0 interface.
> After a reboot, my bridge0 status is:
> [olivier at d630]~>ifconfig bridge0
> bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
> 	ether 82:03:c8:73:85:cc
> 	id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15
> 	maxage 20 holdcnt 6 proto rstp maxaddr 100 timeout 1200
> 	root id 00:00:00:00:00:00 priority 32768 ifcost 0 port 0
> 	member: xl0 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
> 	        ifmaxaddr 0 port 5 priority 128 path cost 55
> 	member: bge0 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
> 	        ifmaxaddr 0 port 2 priority 128 path cost 55
> 
> I need to manually start the dhclient on the bridge0 for getting my IP address:
> 
> [root at d630]~#dhclient bridge0
> DHCPREQUEST on bridge0 to 255.255.255.255 port 67
> DHCPNAK from 192.168.100.254
> DHCPDISCOVER on bridge0 to 255.255.255.255 port 67 interval 6
> DHCPOFFER from 192.168.100.254
> DHCPREQUEST on bridge0 to 255.255.255.255 port 67
> DHCPACK from 192.168.100.254
> bound to 192.168.100.58 -- renewal in 432000 seconds.
> 
> I'm ussing current:
> [root at d630]~#uname -a
> FreeBSD d630.freenas.org 8.0-CURRENT FreeBSD 8.0-CURRENT #14: Thu Mar
> 12 14:17:22 CET 2009
> root at d630.freenas.org:/usr/obj/usr/src/sys/DellD630  amd64
> 
> What is the good rc.conf parameters for using a dhclient on a bridge interface ?

The problem here is that bridge doesn't generate link state events
and thus dhclient never runs.  A workaround would be to change DHCP
to SYNCDHCP which should work assuming the interface that can see the
dhcp server comes up before dhclient gives up.

-- Brooks
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-current/attachments/20090313/ff0227f7/attachment.pgp