Single organizations with multi-homed, discrete networks

Sweeting, John John.Sweeting at
Wed May 9 11:51:30 EDT 2001


Thank you for the reply. I think I knew the answers but I am trying to help
Richard get the ball rolling on discussing these issues and trying to come
up with a policy where the answer could be "Yes" for this type of situation
as well as the situation that Richard describes. I am interested in whether
you believe that the current policy is fair and if so why? and if not again
why? Also it would be great if you could provide some suggestions on how to
make the policy better if you feel it should be changed. Thanks again.

-----Original Message-----
From: Joshua Abbott [mailto:cowsert at]
Sent: Wednesday, May 09, 2001 11:46 AM
To: Sweeting, John
Subject: Re: Single organizations with multi-homed, discrete networks

John, there is no other way for ARIN to track assign/alloc other than
And the answer to your second questions is "NO".


----- Original Message -----
From: "Sweeting, John" <John.Sweeting at>
To: <richardj at>; <ppml at>
Sent: Wednesday, May 09, 2001 10:24 AM
Subject: RE: Single organizations with multi-homed, discrete networks

> Richard,
> I definitely believe that something needs to be put in place to address
> issue. It does not make sense to force an organization to have multiple
> maintainers. Is there a way that ARIN can track assignments/allocations
> useage other than by maintainer id? Another issue would be for
> that wish to use a block of addresses for their backbone/infrastructure
> is seperate from what they assign/allocate to their customers. Example:
> A wishes to expand their network, have just received a /19 for
> assignment/allocation to customers, and want to get a seperate block to
> for the expansion. Under current rules would they be able to receive
> additional address space from ARIN?
> -----Original Message-----
> From: Richard Jimmerson [mailto:richardj at]
> Sent: Wednesday, May 09, 2001 8:17 AM
> To: ppml at
> Subject: Single organizations with multi-homed, discrete networks
> During the open microphone session at the ARIN public policy
> meeting last month the issue of single organizations with
> multi-homed, discrete networks was raised.
> When these organizations receive an allocation from ARIN, they
> split it up and assign a minimum of a /20 to each multi-homed,
> discrete network.  There is a concern that a longer prefix
> would be filtered.  Although this satisfies their concerns about
> filtering, it often conflicts with ARIN's policy for requesting
> additional IP address space.  ARIN's policy states an organization
> must demonstrate 80% of their previous allocation is efficiently
> utilized before their request for additional IP address space will
> be reviewed.
> Apply the following scenario:  An ISP receives a /18 from ARIN and
> splits it up into four /20s -- one for each of their multi-homed,
> discrete networks.  After some time, one of those networks may
> have utilized 75% of its /20, but the others may be growing at a
> slower rate and only be at 25% each.  The network that is at 75%
> would soon need additional IP address space, but the overall
> utilization of the /18 obtained from ARIN would only be at 37.5%.
> This would prevent that organization from meeting the criteria
> for obtaining additional IP address space from ARIN.
> Knowing this to be the case, the ISP may elect to justify a
> separate maintainer account with ARIN for that single multi-
> homed, discrete network.  This eliminates any consideration
> of the growth rate of the other networks when applying for
> additional IP address space.  If an ISP was to do this for
> other networks they would soon have many maintainer accounts
> open with ARIN.
> Should ARIN make a change to its policy that takes this issue
> into consideration and prevents organizations from having to
> open multiple maintainer accounts to meet the IP addressing
> needs of their multi-homed, discrete networks?
> This question is posed as a continuation of the discussion
> that took place at the recent public policy meeting.  Your
> feedback is requested.
> Richard Jimmerson
> Director of Operations
> American Registry for Internet Numbers (ARIN)

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