Renumbering, was: [NANOG] Multihoming for small frys?

Wed May 21 20:38:14 UTC 2008

David Coulson wrote:
> Deepak Jain wrote:
>> Can we all agree that while renumbering sucks, a /24 (or less) is a 
>> pretty low-pain thing to renumber (vs. say, renumbering a /20 or 
>> shorter prefix?) In an ideal world, you never have to renumber because 
>> your allocations were perfect from the get-go.
> Depends - If you're an Enterprise where 90% of the equipment is managed 
> by people who work in the same building, it's not horrible. I renumbered 
> a bunch of /20s onto a /18 where 75% of the equipment was not in my (or 
> the company's) control. That sucked big time.
> 

Right, but a /20 is a /lot/ more space than a /24. I think I'd say that 
shorter than a /21 is certainly a decent threshold of pain (personally). 
Even if its all in-house.

There are ways to make it less painful and special painless cases (an 
all NAT space), but as a shot-in-the-dark, that's a pretty good bet [you 
almost certainly have a decent mix of network and server gear, different 
authorities, different topologies, etc]

DJ