reuse IS-IS/OSPF interfaces

ilPiratailPirata Registered Users Posts: 2 ■□□□□□□□□□
hi, i was wondering if I can use the same interface address but on a seperate link (and different router) within the same network area. i know that having routers with the same Router ID/System ID within the same area can cause problems, but was wondering if i can reuse interface addresses. The interfaces being used are within a seperate /24 compared to the Loopback addresses being used for the Router ID/System ID. i was wondering if i used for example between two routers in one part of the network if i could reuse that same /31 between two (different) routers somewhere else in that same network?


il Pirata


  • daveybdaveyb Member Posts: 28 ■□□□□□□□□□
    This might work, but sounds like a terrible idea. I wouldn't even try it.
  • d4nz1gd4nz1g Member Posts: 464
    Well, I see no problem of doing this if you are using these links only as transit links. This would imply that you wouldn't use those interfaces except for adjacencies and transit traffic. Therefore, you wouldn't even generate labels for these links.

    Another thing you might try is to configure a loopback address and, on all your point-to-point links, use the ip unnumbered interface command.

    By any means, I would never do this on a production network.
  • networker050184networker050184 Mod Posts: 11,962 Mod
    I'd look into OSPF prefix suppression if you want to go this route.
    An expert is a man who has made all the mistakes which can be made.
  • ilPiratailPirata Registered Users Posts: 2 ■□□□□□□□□□
    The OSPF Prefix suppression is an interesting option and one we are now testing out. from the initial testing it looks as tho there has been some improvement in the OSPF convergence time :) A lot more testing will be done. The network this is being done on, is purely a test environment where we are looking at various implementation options and noting the pro's and con's of certain approaches. thanks again for all your advice.

    il Pirata
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