Approach to allocating netblocks

Dave Israel davei at
Wed Jan 14 16:17:20 UTC 2009

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 now
> split out and divide to our customers.
> What's the best approach to handing out /30's, /29's, etc. that is efficient
> 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 divide
> and conquer approach by allocating the first /30, for example, as 0 and 128,
> 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.
> Ideas?
> Frank

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