[HECnet] ROOSTA routing problem

[Johnny Billquist]

On 2011-12-27 12.05, hvlems at zonnet.nl wrote:
Isn't the problem similar to what happens if there would have been two active bridges between two ethernet segments?

Sorry for being offline a couple of days...
Anyway, the answer to that one is no (maybe someone else already replied, I have over 200 unread after the spam filtering have run over my inbox).

If you have two active bridges between two ethernet segments one of two things happen.
1) The bridges realize this, and shut one of them down.
2) The bridges don't realize this, and starts sending packets around in a never ending loop, causing havoc.

My bridge program falls in category 2. Any sensible ethernet switch you might have at home hopefully falls into category 1.
The normal way of implementing category 1 is by having the switch implement the spanning tree protocol to detect possible loops.

	Johnny


------Origineel bericht------
Van: Peter Lothberg
Afzender: owner-hecnet at Update.UU.SE
Aan: hecnet at Update.UU.SE
Cc: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] ROOSTA routing problem
Verzonden: 27 december 2011 18:43

    Hmmm.. LEGATO can't talk to ROOSTA ("remote node not currently reachable")
even though there's a direct Multinet link to ROOSTA (and yes, the link is
UP and working).



    I think the problem is that ROOSTA is in area 6, and the area router for 6
is STAR69.   Trouble is, STAR69 doesn't have a path to ROOSTA and doesn't
know how to send it packets.



    (It doesn't help that STAR69 still thinks that ROOSTA is 3.34 - it moved
to 6.134 a while ago - but I don't think that's causing the problem.)


Multinet links metric 5
Bridged ethernet metric 10
Set all multinet-link nodes Level2-Area-Routers

--P