Home page logo

nanog logo nanog mailing list archives

Re: Approach to allocating netblocks
From: "Jason Biel" <jason () biel-tech com>
Date: Wed, 14 Jan 2009 10:34:29 -0600

Customer should have the forethought to request the right amount of space to
include for growth.

If customer requested more space, rather than grow into another adjacent
block, we would just assign them an additional block elsewhere in the
overall subnet, and route both blocks to them.


On Wed, Jan 14, 2009 at 10:30 AM, Frank Bulk <frnkblk () iname com> wrote:

I see what you're saying, but what if the customer whom you assigned the
0/30 to wants a larger block...rather than making them renumber (which in
the case of a small customer, is a very painful experience because of all
the DNS and router/firewall reconfiguration issues that they don't normally
deal with and therefore cause their service provider (us) and their
consultant a lot of grief), I would want to give them 0/29.  But if the
is already assigned to someone else, I'm stuck.

But perhaps the BCP is to make the customer renumber, in which case I'm
making things more complicated than they need to be.


-----Original Message-----
From: Dave Israel [mailto:davei () otd com]
Sent: Wednesday, January 14, 2009 10:17 AM
To: frnkblk () iname com
Cc: NANOG list
Subject: Re: Approach to allocating netblocks

If most of your allocations are small, and you don't plan on growing
them very often, you'll probably do better with starting at the ends and
working your way inward.For example,. for /30s, allocate 0/30,  then
4/30,  248/30, and 252/30 before moving in to 8/30, 12/30, 240/30, and
244/30.  That way you're preserving larger netblocks for as long as
possible before breaking them up.

Frank Bulk wrote:
For the first time we have our own ARIN-assigned netblocks that we can
split out and divide to our customers.

What's the best approach to handing out /30's, /29's, etc. that is
as possible but allows for customers to expand their allocation to a
neighboring block?

I was thinking of having one /24 for each block size, and then do the
and conquer approach by allocating the first /30, for example, as 0 and
then next two at 64 and 192, etc.  Once there's only one /30 free between
each allocation, I would start using another /24.  Of course, that would
mean 50% (or less) utilization.



Jason Biel
jason () biel-tech com

  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]