[eng/rtg] changing loopbacks

Thu Sep 29 18:24:14 UTC 2005

Are you using any logging-source or source interface for your 
authentication on the boxes?  I've found that most versions of IOS 
require a reboot to accept a change of these.

Similarly, OSPF under IOS will need a bounce/reboot to change it's 
router-ID if you are using the loopback for that.

Personally, the cleanest way I've been able to accomplish changing this 
in regard to OSPF, logging and authentication on Cisco's is to suck 
down the running config, make the changes in your editor of choice, 
push it back up to startup-config and schedule a reboot.  iBGP is much 
easier to make the changes as you outline.

As always, your mileage may vary.

David

On Sep 29, 2005, at 11:05 AM, Randy Bush wrote:

>
> so i have junipers, ciscos, and a few <gasp> zebras in an ospf
> and ibgp mesh.  they're peering via loopbacks, of course.
> unfortunately, i need to recover the space from which the
> loopbacks are taken.  of course, i would like to do so with
> minimal disruption.  i am thinking of something like the
> following:
>
>   o add second loopbacks to all routers with new address in new
>     block
>   o set up ibgp peerings to new addresses from existing
>     peerings
>   o change the source of routing updates to new addresses
>   o remove old peerings
>   o remove old loopbacks
>
> what [else] am i missing?
>
> randy
>