loopback interface and when to create them

Folks:
I am reading about loopback interfaces; however, I am trying to understand when I would create these interfaces. In addition, is it a wise idea to always create a loopback interface on at least one interface of a router?

Thanks.

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Comments

MosGuy

Loop backs are useful when you don't have additional PC's to plug in or want to simulate basic internet connectivity through ping or trace route. Personally I don't create them on every router. Normally only end routes i.e: a LAN or an "internet" connection. You can certainly add them on every router to simulate multiple sub-nets. Usually for me one of two IPs is enough to test ping & trace route. But it all depends on the lab or scenario I'm working on.

billyr

You'll also find them useful when you implement OSPF or BGP.

SteveO86

The nice thing to remember about loopback interfaces is they are always on, meaning as long as the router has power and is operational the loopback interface will be pingable.

ccnaomkar

loopbacks usually used in ospf router id for ccna level exams and for additonal pc requirenment

just remember these things for ccn

there are lot of uses of loopback as u will go in advance studies

ccnaomkar

loopbacks usually used in ospf router id for ccna level exams and for additonal pc requirenment

just remember these things for ccna

there are lot of uses of loopback as u will go in advance studies

e24ohm

Thanks folks!!!

odysseyelite

I had to create a loopback while labbing this weekend. I did not want to drag out another PC just to see the network information being sent with RIP.