nanog mailing list archives

Re: IPv4 Mismanagement


From: Justin Streiner <streinerj () gmail com>
Date: Fri, 2 Oct 2020 17:44:13 -0400

I suspect many providers don't have good business processes for reclaiming
IP space that was assigned to customers who have either disconnected or
voluntarily returned the space.

The provider I started out with in the mid/late 90s bootstrapped itself
with IP space from MCI (now, CenturyLink... I think?) and UUNET (now
Verizon Business), but we handed those blocks back when we started getting
provider-independent space from ARIN.  No idea what became of that space
after we stopped announcing it.

jms

On Fri, Oct 2, 2020 at 3:38 PM Ryan Wilkins <ryan () deadfrog net> wrote:

I have the same thing with a service that was disconnected a couple years
ago.  Four IP blocks of /24 size are still swipped to us and we’re
announcing them.  I don’t put any customers on them and just use them for
temporary things for fear that some day someone will want them back.

On Oct 2, 2020, at 2:50 PM, Matt Brennan <brennanma () gmail com> wrote:


A service I disconnected more than 2 years ago still has a /24 of their
space SWIPED to me. Their NOC closed the ticket I opened to remove. Unknown
if it's actually in use for another customer.

I also had a conversation last week with another ISP (we were
renegotiating our contract) about this. The order form they sent me had
multiple /28's we had "given back" years ago still listed. Turns out
they're still being routed to us as well.

I would bet it happens all over the place.

-Matt

On Fri, Oct 2, 2020 at 2:00 PM Matt Hoppes <
mattlists () rivervalleyinternet net> wrote:

I'm sitting here in the office on a Friday performing some IP
maintenance and I see that one of our upstreams is still filtering an IP
range we haven't used in years.   I dig into it a bit more and it turns
out a major carrier still has them SWIPed to us.

This got me curious and I dug more into IPs from back in our early days
and discovered there are two Tier-1 carriers we no longer do business
with that still have large blocks of their own IPs SWIPED and allocated
to us.

This is really confusing and concerning.   I know it's not the
end-all-be-all, but I wonder how much IPv4 exhaustion is being caused by
this type of IPv4 mis-management, where IPs are still shown as
"allocated" to a customer who hasn't used them in years.

I've seen this behavior from Frontier and CenturyLink to name just a few.

Any thoughts on this?




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