[HECnet] "Poor mans routing" and the Italian Hobbyist DECNET

[Kari Uusim ki]

On 29.6.2012 12:31, Peter Coghlan wrote:
Kari wrote:

On 28.6.2012 23:28, Rok Vidmar wrote:
I don't think that will work.

        How about a bridge translating HECnet's area 1 to an
    area unused in Italian net and translating Italian area 1
    to an unused area in HECnet?
    --
    Regards, Rok

.


That's exactly what an ATG (Address Translation Gateway) does. Although
I haven't used it over TCP/IP (Internet in this case). Maybe it would
work if it is configured in either end of a GRE tunnel. Could be worth
testing.


I can't find my Cisco manual

The Cisco DECnet configuration guide can be found at:
http://www.cisco.com/en/US/docs/ios/decnet/configuration/guide/configuring_decnet.pdf

but I've gone looking for suitable configuration
commands on my router and I found:

decnet map N.H <0-3> N.H                             Establish an ATG address mapping

The first N.H is described as "Local virtual DECnet address"
The number between 0 and 3 is the "Remote ATG network number"
The second N.H is described as "Remote real DECnet address"

I also find that it is possible to apply:

decnet <0-3>                       ATG network number

to each interface and it can also be applied globally. Presumably my current
decnet configuration defaults everything to being in ATG network number 0.

Can you describe how this can be used to map addresses between conflicting
areas?

Let's assume the most usual conflict is at hand, where two different ogranisations use area 1, but neither the networks nor the areas can be merged, but the organisations need to communicate using DECnet.
Organisation A applies in the router the DECnet map for Organisation B where the B's real area 1 is chosen to have a virtual area of 24 (which is not used in either networks). Then B assignes a virtual area of 25 to the A's real area 1. Then they configure their routers to use DECnet map and the result looks like:

A			Cisco ATG				B

1.1 ----------------->	24.1 --------------------------------> 1.1
1.2 ----------------->   24.2 --------------------------------> 1.2
1.3 ----------------->   24.3 --------------------------------> 1.3
1.4 ----------------->   24.4 --------------------------------> 1.4

And in the opposite direction it looks like:

A

1.1 <------------------	25.1 <-------------------------------- 1.1
1.2 <------------------ 25.2 <-------------------------------- 1.2
1.3 <------------------ 25.3 <-------------------------------- 1.3
1.4 <------------------ 25.4 <-------------------------------- 1.4

If there aren't any other conflicting areas, all other areas can be routed normally.




Alternatively, if someone on the Italian network or a test network isolated
from hecnet is willing to set up another tunnel to me, I am willing to have a
go and see if I can get it to work.

I could set up a test with you.

The commands available seem to suggest an individual mapping is required for
every host. Is it also possible to map a whole area with a single mapping?

It didn't use to be, but the manual says it should be possible on some release 12's but not all.

Regards,
Peter Coghlan.

.


Regards,

Kari