[HECnet] DECnet map, was Re: DECnet/Python

[Johnny Billquist]

On 2021-11-05 20:01, Paul Koning wrote:
> 
> 
>> On Nov 5, 2021, at 1:23 PM, Dave McGuire <mcguire at neurotica.com> wrote:
>>
>> On 11/5/21 1:11 PM, Paul Koning wrote:
>>> Yes, that's a typical issue.  Or DNA-compliant equipment that has NICE turned off or restricted.  I looked into using the DECnet MIB to get information out of Cisco routers but that didn't seem to be practical.
>>
>>   I think Brian has done some work in that area.  Or maybe that was just config stanza injection.
>>
>>> If a Cisco router is visible from a compliant router, it should appear.
>>
>>   ...and it does, with two tunnels that Peter and I just brought up a few minutes ago.
>>
>>> But if you have a Cisco router behind another one, the behind one won't be mapped unless there is another router in the same area, one that does speak NICE, so it's seen as reachable.
>>
>>   So putting a Py router just *on* the network here, separate from the GRE tunnels on the Cisco?
> 
> The best case is to be able to see the circuits that connect to the router, since that will show those on the map.  Next best is to know the node is reachable.  If there is another router in the same area that answers NICE requests, I'd see the list of reachable nodes.
> 
> If all you have visible via NICE is level 2 connectivity out of area, and no circuits (none of the NICE nodes are adjacent) then I can't tell the node is reachable.  If it's up it would make its area reachable in the L2 routing table, but that doesn't tell me which specific L2 router is offering that reachability.
> 
> So yes, if you take a previously unexplorable area and stick a  router into it that answers NICE -- such as PyDECnet -- then the mapper can suddenly display it more accurately.

It obviously helps a lot, but the mapper is still blind to what 
connections the Cisco box actually have. Some can be inferred by looking 
at the other end, if that end talks NICE, but it obviously fails if both 
sides don't speak NICE. Even a ping functionality have limited use, 
since then also would only be able to tell that the node is up, but not 
figure out connections out.

I've sortof grown a slight dislike of Cisco boxes for this reason. Not 
being able to diagnose things with NICE is really a pain sometimes.

   Johnny

-- 
Johnny Billquist                  || "I'm on a bus
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