duplicate epair ipv6 addresses

Frank Razenberg frank at zzattack.org
Thu Sep 2 14:15:46 UTC 2010


  Hi Bjoern,

I do have an openvpn setup which also creates a bridge. At one point in 
time it conflicted with the bridge0 interface used for the jails. The 
openvpn 'up' script did the following:

#!/bin/sh
/sbin/ifconfig bridge0 create
/sbin/ifconfig bridge0 addm nfe0 addm $dev up
/sbin/ifconfig $dev up

It may have executed a couple of times while bridge0 already existed and 
had the epairs as members. I don't recall the epair's 'a'-end having 
different ethernet addresses before, but I haven't specifically looked 
at them. I don't believe I do any manual collision detection.
I'm not sure whether this answers your questions, if you need any more 
info please let me know.

Frank

On 9/2/2010 3:51 PM, Bjoern A. Zeeb wrote:
> On Thu, 2 Sep 2010, Frank Razenberg wrote:
>
> Hey,
>
>> base
>> nfe0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> 
>> metric 0 mtu 1500
>>        options=80008<VLAN_MTU,LINKSTATE>
>>        ether 00:22:15:bb:6d:6f
>>        inet 10.31.45.10 netmask 0xffffff00 broadcast 10.31.45.255
>>        media: Ethernet autoselect (1000baseT <full-duplex>)
>>        status: active
>> lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
>>        options=3<RXCSUM,TXCSUM>
>>        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x2
>>        inet6 ::1 prefixlen 128
>>        inet 127.0.0.1 netmask 0xff000000
>>        nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
>> bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 
>> mtu 1500
>>        ether de:3b:7a:d8:3a:98
>>        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: epair2a flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
>>                ifmaxaddr 0 port 6 priority 128 path cost 2000
>>        member: epair1a flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
>>                ifmaxaddr 0 port 5 priority 128 path cost 2000
>>        member: epair0a flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
>>                ifmaxaddr 0 port 4 priority 128 path cost 2000
>>        member: nfe0 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
>>                ifmaxaddr 0 port 1 priority 128 path cost 55
>> epair0a: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> 
>> metric 0 mtu 1500
>>        ether 02:9a:c6:00:04:0a
>> epair1a: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> 
>> metric 0 mtu 1500
>>        ether 02:da:d1:00:05:0a
>> epair2a: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> 
>> metric 0 mtu 1500
>>        ether 02:ea:c6:00:06:0a
>
> What makes me wonder is why the ether addresses of all three "a"
> epair ends are non-default?   Do you know what changed them?  Did you
> do do avoid collisions with possibly other epairs bridged to a 2nd
> machine over nfe0?
>
> /bz
>



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