Loopback - why needed ?

Hi ! in the last few sample configurations i came across the term LOOPBACK. what is this device needed for and why do i have to specify this. concerning FRAME RELAY or ISDN for example. thanx a lot === Hans Schimek Student Fachhochschule St. Pölten f. Telekommun

Re: Loopback - why needed ?

A loopback interface will only go down if the entire router goes down. Loopback interfaces should be used for OSPF, BGP, and DLSw+. For instance, when a loopback interface is used on a router using OSPF, the highest number IP address on a loopback interface is used as the Router ID. If the Router

e: Loopback - why needed ?

if you did no keepalives on an ethernet it would do the same thing (despite caveats) would it not? also, is there any scenario that you would have / advertise a route to loop0? XX A loopback interface will only go down if the entire router goes down. L