[HECnet] Router for area 1

[Johnny Billquist]

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