6506 loopback interface

We have a single 6506 which we will replace with two 6506 in HSRP redundancy mode. Until now we don't have a loopback interface configured on the 6506. Most management articles advise the use of the loopback interface so we want to configure it on both the 6506's. What we can't find, is what kind of address to put on both machines. Loopback addresses seem to be host adresses but how are they related to each other ?

If we give router A address x.x.y.1, can we give router B address x.x.y.2 or do we need to give it x.x.Z.1 so i need a separate subnet for each interface ? If one uses active routing, is this host route also propagated ?

I've been looking on the cisco website and google, but i can't find a decent reference on configuration and use of loopback interfaces. If you have a pointer for me, please let me know.


Wim Holemans Network Manager University of Antwerp

Reply to
Wim Holemans
Loading thread data ...


Take an address range big enough for number of your devices. Suppose it's N.N.N.0/24. Then you assign N.N.N.x/32 to loopback0 on each device, where x runs from 1 to 254. You must either enable routing on loopback (e.g. add 'network' command to your 'router ospf') or redistribute connected (use route-map to control what is being redistributed). You're done.


Reply to
Charlie Root

You do not indicate whichj routing protocol that is being used.

If you wre using OSPF or ISIS then you would want to assigna range of addresses for each area. This would be done to allow to addvertise summary addresses for the entire block fopr a specifici area

Loopback could be a block at the beginning of the blocks assigned to each area or the top of the same address range.

Reply to

There is no special REQUIREMENTS for Catalyst 6506 to have any Loopback interfaces configured. HSRP protocol does not require a Loopback Interfaces as well. You may require to create a loopback interface for a "special cases", i.e. OSPF protocol, Policy Based Routing, NAT-on-the-stick, etc. But all these cases will depend on WHAT you need to achieve.

Good luck,


Reply to

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.