Splitting DS3 into two OSPF circuits

[jmcoffey]

I have a DS3 circuit between two ABRs. Presently the circuit is in area 1 and a virtual link is configured between the two for proper routing. I am changing this area to a NSSA area. In order to maintain optimal routing I now need two(2) circuits between these ABRs one in area 1 the other in area 0. I do not want a $econd DS3 circuit. Is it possible to use a mux/demux at each end to split this existing DS3 circuit into two separate circuits at the routers?

Thanks in advance for any info,

Jim Coffey

[m.gamal]

Hi Jim again

well i guess if u make two subinterfaces on this DS3 circuit with two different IP addresses and if u put each subinterface relating to n OSPF area..it should work without another DS3 or a MUX/DMUX

hope it works

[jmcoffey]

Good thought, I hadn't thought of that. BUT I do not think this will work since OSPF adjacencies will only be formed over primary networks and not secondary networks.

[m.gamal]

it is not a secondary IP address..i think he will treat it as a normal interface..as it is having its own IP , and it is not a secondary ip on the same interface.

try it , or if u r not in a hurry..i can test it for u :)

my lab is still alive

[bbranch]

How about using a GRE tunnel between a loopback interface on each router, route the tunnel over the DS3 and place it in OSPF Area 1 and the DS3 itself in OSPF Area 0

[jmcoffey]

The GRE tunnel seems a little complicated to me and I believe in KISS (keeping it simple) :-)

I am not knowledgable of how sub-interfaces function or their configuration :-( . This DS3 is a single physical point-to-point leased line. Will sub-interfaces take a single physical line and treat it as two logical (virtual) interfaces? How will OSPF treat this? I guess I need to study up on sub-interfaces etc. ;-)

If Mohamed can test this in his lab it would be helpful (Thanks, Mohamed.)

Maybe we'll all learn something.

Jim Coffey