nanog mailing list archives

Re: Post-Exhaustion-phase "punishment" for early adopters


From: Joel Jaeggli <joelja () bogus com>
Date: Wed, 09 Feb 2011 09:21:09 -0800

On 2/9/11 4:35 AM, Sam Stickland wrote:


On 9 Feb 2011, at 02:43, "R. Benjamin Kessler"
<Ben.Kessler () zenetra com> wrote:

From: George Herbert [mailto:george.herbert () gmail com]

"Let's just grab 2/8, it's not routed on the Internet..."

+1

I was consulting for a financial services firm in the late '90s
that was acquired by a large east-coast bank; the bank's brilliant
scheme was to renumber all new acquisitions *out* of RFC1918 space
and into (at the time) bogon space.

If I recall, some of the arguments were "they were too big to fit
into RFC1918 space" and by having all of their divisions in
non-RFC1918 space it would make it easier for them to acquire new
companies who used RFC1918 space internally.


You don't have to trawl back to the late 90's to find this, I know of
at least 3 or 4 large enterprises using large chunks of public
address (multiple /8's) that aren't their's /today/.

This "works" because 1) the Internet is only accessed through
proxies, 2) devices that require direct Internet access are addressed
out of registered address space (or NATed to registered address
space), and 3) third party connections to others enterprises are
usually src/dst NATTed to the enterprise's own ranges (with the added
benefit that this NAT at 3rd party boundaries helps ensure symmetric
traffic flow through firewalls).

sotime it works... if you are natted (from your public scoped but
overlapping ipv4 address) but don't go through a proxy, or you go
through a transparent proxy you may still be dead because the internal
route covers you destination. Those aren't just enterprises either, some
fairly common offenders are ISPs or wireless carriers and they did use
just one or two additional /8s...

joel

And I've only worked at 3 or 4 large enterprises so it's probably
safe to assume there's more! With my SP background I was shocked and
I'm not trying to defend this practice, but in the enterprise land it
seems accepted.

Sam




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