Avi, Could you use loopback interfaces to do what you want? -alan ps i'm not really a fan of ip unn, I think /30 serial networks should be considered responsible allocation by most all parties. pps i'm really a big fan of loopback interfaces for the purposes of monitoring a router as a node, as opposed to the plurality's idea of an interface having a cpu ......... Avi Freedman is rumored to have said: ] ] > The biggest problem with using non-routable ip addresses on numbered interfaces ] > whether point to point or frame or atm or whatever, is that you lose outside ] > connectivity from those interfaces. We tried this, but the essential ] > traceroutes from our core routes are too important when debugging BGP ] > problems to the outside. ] > ] > Robert Bowman ] > Exodus Communications Inc. ] ] Exactly. Especially when you have downstream customers who only announce ] routes via BGP to you and/or other providers, it can be important for them ] to be able to trace out with a source address that has global connectivity. ] ] We usually use unnumbered interfaces, though, for singly-connected customers ] (unless their routers can't support unnumbered interfaces). The only ] major gotcha with that is that if they're using a Real Router (that deleted ] routes associated with interfaces that aren't available), you can't ] get to their router if their ethernet is down... ] ] Avi ] ] ]