[HECnet] Router for area 1

[Johnny Billquist]

Hmm. I'm pretty sure that the routing priority is used to select which router to use as the area router as well. But I should recheck documentation.
I might be misremembering things (which aren't that unusual), and it's been several years since I last looked at this.

	Johnny

On 2012-01-06 00.17, hvlems at zonnet.nl wrote:
Routing priority doesn't affect the selection of the active area router if more than one exists in an area. The only arbitration is node address : highest address wins.
-----Original Message-----
From: Johnny Billquist<bqt at softjar.se>
Sender: owner-hecnet at Update.UU.SE
Date: Fri, 06 Jan 2012 00:11:54
To:<hecnet at Update.UU.SE>
Reply-To: hecnet at Update.UU.SESubject: Re: [HECnet] Router for area 1

On 2012-01-05 17.21, Bob Armstrong wrote:

I wrote-
	OpenVMS Network status for local node   2.1 LEGATO on   5-JAN-2012
08:11:19.43

                          Area     Cost   Hops       Next Hop to Area

                              1           4         1           QNA-1         ->       1.300   CTAKAH
		....

      It bugs me, although I can't point at an actual problem that it causes,
that the routing node for area 1 is seen as CTAKAH, rather than MIM.   Since
CTAKAH is not actually local to Uppsula (I think that's where MIM is) but is
rather at the other end of yet another bridge, this means that any traffic
for area one, no matter what its ultimate destination, has to make an extra
round trip to Russia.

      This happens because when there are multiple routing nodes for the same
area, DECnet uses the one with the highest address.   The obvious solution
would be for Johnny to renumber MIM as, say, 1.1023.

Nah. MIM have a higher routing priority set. (Unless Oleg Safiulling
have tweaked the routing priority of CTAKAH.) However, you sometimes run
into this issue because there are so many routers on the bridge.
Depending on your configuration, some routers will be ignored, and which
ones seems to be somewhat random. So unfortunately, it can be MIM that
gets tossed, and then it don't matter that MIM have a higher priority.

But yes, CTAKAH do sit in Russia, and it causes packets to travel some
extra time to get to places. But apart from that, it should not ever be
an issue. A slight side effect of the fact that we fake a local ethernet
segment. Had it been a real one, the packets would travel the same on
the local segment, no matter which router was used.

	Johnny