if_bridge interface confuses Windows Small Business Server 2000

[Erik Osterholm]

On Tue, Nov 15, 2005 at 08:43:18AM -0500, Steve Bertrand wrote:
> 
> > FreeBSD 6 came at the perfect time for me.  I've just 
> > switched my primary desktop from Win2k to FreeBSD, and I put 
> > the Windows boot disk in an old machine that was heading for the skip.
> > 
> > I wanted to access the W2k machine (fred) over VNC without 
> > flooding our switch, so I thought let's take advantage of the 
> > new features in REL 6...  I added a second ethernet card to 
> > my FreeBSD box (alfie) and configured a bridge in /etc/rc.conf:
> > 
> > 	ifconfig_rl0="DHCP"
> > 	ifconfig_rl1="up"
> > 	cloned_interfaces="bridge0"
> > 	ifconfig_bridge0="addm rl0 addm rl1 up"
> > 	gateway_enable="YES"
> > 
> > SBS is configured to give a static DHCP lease of 
> > 192.168.0.181 to alfie; fred is dynamic and is currently 192.168.0.35.
> > 
> > At first everything seemed fine, and fred operates as if it 
> > was plugged straight into the network.  
> > 
> > But...
> > 
> > 1) SBS sees both machines as alfie, even though it correctly 
> > reports the MAC addresses of each machine
> > 
> > 2) On alfie, when I want to make a VNC connection to fred I 
> > have to type "vnc viewer alfie"(!)
> > 
> > 3) On fred, if I ping alfie it returns 192.168.0.35 as the IP 
> > number, not 181 which is the static lease.
> > 
> > 
> > I assume this is a bug in if_bridge, only because I assumed 
> > that bridge 
> > interfaces should be transparent (and act like a physical switch).
> > 
> > When we get some small switches in I'll use one to connect 
> > the two machines 
> > together, but I'd still like to work out what's going on 
> > here.  Am I doing 
> > something wrong?
> 
> I'm a wee bit confused here, but I do understand what you are trying to
> do.
> 
> First, did you compile a new kernel with the following option?:
> 
> options BRIDGE

This should not be necessary with if_bridge.  A kernel module must be
loaded before if_bridge will work, but seems to load automatically
when creating the bridge interface.  Alternatively, if_bridge can be
compiled into the kernel with the following line:

device if_bridge

I've even read where the bridge(4) bridging mode is deprecated.  Does
anyone know if this is accurate?

> Second, try giving both PC's a static IP address, and disconnect the
> FBSD box entirely from the network (so you essentially have a 2 pc
> network), then commence testing.
> 
> HTH,
> 
> Steve
> 
> > 
> > 
> > Ashley

Erik