[HECnet] Multinet peerings...?

[Johnny Billquist]

On 2016-01-14 21:38, Peter Lothberg wrote:
>>
>>> On Jan 14, 2016, at 3:02 PM, Peter Lothberg <roll at Stupi.SE> wrote:
>>>
>>>> The values are somewhat arbitrary; it doesn't really matter what
>>>> scheme you use but if you are inconsistent the routing may be
>>>> surprising.
>>>>
>>>> The routing spec has a suggested algorithm (100,000/line speed)
>>>> which may have made sense in the old days but for modern networks
>>>> isn't terribly useful.
>>>> 	paul
>>>
>>> What I wanted to get to was a scenario where traffic was symetric
>>> between two nodes, eg, use the same links from a-b as b-a, it makes it
>>> much easier to understand what's wrong when things behave funny...
>>
>> If costs are the same at both ends of a link, that will certainly
>> help.  Then again, it is quite possible for two paths to have equal
>> cost, and if so, DECnet implementations will pick one of the two, in
>> a way that is not specified.
>> 	paul
>
> If all links in HECNet where point-to-point, with the same metric on
> both sides, it will most likely be almost *perfect* by itself.
>
> The complex movie is when they *THINK* they are all on the same
> ethernet with metric 1.....

Well, in all honesty, default cost for ethernet links in VMS is 4, and 
in RSX is 3...
So, if you want to favor a different link, set the cost to less.

But you are blindly assuming that Multinet (or other) point-to-point 
links are better. That one I still do not see. There are definitely 
cases where it can be worse.
The worst thing about the bridge is, as I wrote in another mail, is when 
you are on an ethernet segment, and you want to talk to a different 
area, which have several area routers on that same ethernet segment you 
are on, in which case you might end up going through pretty bad hopping.

	Johnny