Subject: bridge trouble?
To: None <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-kern
Date: 04/04/2005 16:40:33
I'm trying to set up OpenVPN bridging between two Ethernet networks.
(This is all on 2.0, i386 in case it matters.)  I had it all working,
but then I left the machines up over the weekend, and now I find it
doesn't work.  When looking for the reason, it seems to be that bridge0
has gone wonky on one of the machines.

Specifically, even though brconfig still shows both tap0 and rtk0 as
belonging to the bridge, broadcast packets (ARP requests, to be
specific) received on rtk0 do not make it out tap0 (according to

I also note that bridge0 seems to have gone weird in another way.
brconfig prints

bridge0: flags=41<UP,RUNNING>
                priority 32768 hellotime 2 fwddelay 15 maxage 20
                ipfilter disabled flags 0x0
                tap0 flags=3<LEARNING,DISCOVER>
                        port 11 priority 128
                rtk0 flags=3<LEARNING,DISCOVER>
                        port 1 priority 128
        Address cache (max cache: 100, timeout: 1200):
[50 perfectly reasonable-looking lines snipped]
                00:11:2f:9a:34:95 rtk0 20 flags=0<>
                00:11:43:72:16:19 rtk0 4294967151 flags=0<>
                00:50:fc:21:01:3e rtk0 4294967106 flags=0<>
                00:0d:61:12:fe:f5 rtk0 4294967094 flags=0<>
                00:10:83:9c:a7:59 rtk0 4294967066 flags=0<>
                00:50:da:1e:e5:ea rtk0 4294967062 flags=0<>
                00:10:4b:2e:ce:5b rtk0 4294967058 flags=0<>
                00:12:17:d5:be:f6 rtk0 4294967044 flags=0<>
                00:0b:6a:94:03:58 rtk0 4294967041 flags=0<>
                00:06:29:75:65:4c rtk0 4294967028 flags=0<>

Those entries that time out in over 136 years look..wrong.  (Of course,
they're just small negative numbers, -145 through -268, taken as
unsigned here, though the list is obviously sorted as if signed.)

I don't know whether these two problems are related.  I rebooted and
everythin's fine, but I fear if it happened once it can happen again.


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