IP Addresses for colocation

Roger Marquis marquis at roble.com
Sat Jun 23 03:35:38 UTC 2001


Mark J. Scheller wrote:
> Is there a better way to get a /24 that can "go anywhere"?  Or should I just
> justify a /24 at the colocation facility and go through the same process
> should we decide to change?  Is there a way to buy a routable /24?

Not sure I understand the concerns WRT renumbering.  If you have
numerous VPNs and ACLs which are dependent on the IPs then it may
be a little work, but otherwise there's not really much to renumbering
a /24.  Just make sure the new nameservers are in place, the old
TTLs are turned down to 24 hours or so, and the environment is
replicated at the new co-lo.  You can use GRE tunneling and optionally
NAT to do this with even more cut-over transparency.

If you've never done it before hire a consultant to draw up the
project plan and walk you through.  The second time is much easier,
and after that you'll be free to choose a co-lo without needing to
worry if it'll be forever viable.  BTW, no matter what ISP you
choose chances are that at some time in the future you'll want to
move.  Plan on it and you'll sleep a lot easier.

One question for the gurus on this list: if a site were to get a
portable /24 would they be able to assure connectivity to ISPs that
filter small subnets from their BGP?

-- 
Roger Marquis
Roble Systems Consulting
http://www.roble.com/






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