Re: Erratic Bridge

["Joseph C. Bender" <benderjc@benderhome.net>]

At 09:07 PM 6/5/2002 +0200, you wrote:
>On Wed, 5 Jun 2002 11:31:25 -0700 (PDT)
>Daniel Zieber <dlz@astro.caltech.edu> wrote:
>
>> hme0 at sbus0 slot 14 offset 0x8c00000 vector 21 ipl 6: address
>> 08:00:20:92:d4:2c
>> nsphy0 at hme0 phy 1: DP83840 10/100 media interface, rev. 1
>> SUNW,bpp at sbus0 slot 14 offset 0xc800000 vector 22 ipl 2 not
>> configured hme1 at sbus0 slot 1 offset 0x8c00000 vector 4 ipl 6:
>> address 08:00:20:92:d4:2c
>> nsphy1 at hme1 phy 1: DP83840 10/100 media interface, rev. 0
>
>> hme0: DAD detected duplicate IPv6 address
>> fe80:0001::0a00:20ff:fe92:d42c: 1 NS, 0 NA
>> hme0: DAD complete for fe80:0001::0a00:20ff:fe92:d42c - duplicate
>> found hme0: manual intervention required
>
>Aren't MAC addresses supposed to be unique? That might be your problem,
>although I'm not sure.
>
>// nick
>
	Sounds like it.  And yes, they are, but welcome to the wonderful world of
Sun Systems.

All Sun boxen, unless the OpenProm parameter "local-mac-address" is true
and the card has it's own MAC onboard, 
give all of their network interfaces a MAC from their NVRAM on the
motherboard.  

So, bridge two interfaces with the same MAC, and suddenly, arp requests get
a whole lot more interesting.  As do many other operations involving the
MAC address.

It's a boneheaded design decision, but I don't think they ever intended to
have these things run bridging either.
And AFAIK, OpenBSD ignores the local-mac-address parameter, and I can't
find any documentation (but I've not been looking too hard 
here) to disprove that.
You could try setting it, to see what happens:

Also:
<http://marc.theaimsgroup.com/?l=openbsd-tech&m=90741962604829&w=2>  
has a sea.c source code file that was written to set the ethernet addresses
manually, but the post was from 1998, so I don't know if it 
will work with current sources.

If niether of those work, unless someone else has more of a clue about this
(which is probably the case 8-) ), is to use another machine 
that doesn't do MAC addresses in a not quite so braindead fashion.

Or...You didn't really want a bridging firewall, did you?  You could always
use PF/NAT, or subnet your IP space (if you can) and just use PF.


Signing off, 

Joseph Bender
<mailto:benderjc@benderhome.net>
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