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New Member

routers loopback address

Hi, what is a router loopback address, why is it needed?

Thanks

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New Member

Re: routers loopback address

A loopback interface on a router is used as an interface that will never go down.

For instance, OSPF identifies the router with a "router ID". This ID is derived by using the highest IP address of any interface that is "up" when OSPF starts. If a loopback exists, OSPF will use the highest IP address of the loopback interfaces.

You can use loopback interfaces as a destination IP address to the router... for instance, you may wish to peer BGP to a loopback interface on a router instead of using a physical interface so that you can load balance.

NAT uses loopbacks to send packets to itself when you implement NAT on a stick.

Lots of uses for those handy loopbacks! :)

Mick.

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