The Department of Work and Pensions, UK has an entire /8

George Herbert george.herbert at
Fri Sep 21 01:51:41 UTC 2012

On Thu, Sep 20, 2012 at 5:13 PM, Stephen Sprunk <stephen at> wrote:
> On 19-Sep-12 03:46, Alex Harrowell wrote:
>> On the other hand, the scarcity is of *globally unique routable*
>> addresses. You can make a case that private use of (non-RFC1918) IPv4
>> resources is wasteful in itself at the moment. To be provocative, what
>> on earth is their excuse for not using IPv6 internally? By definition,
>> an internal network that isn't announced to the public Internet
>> doesn't have to worry about happy eyeballs, broken carrier NAT, and
>> the like because it doesn't have to be connected to them if it doesn't
>> want to be. A lot of the transition issues are much less problematic
>> if you're not on the public Internet.
> Actually, they're not any different, aside from scale.  Some private
> internets have hundreds to thousands of participants, and they often use
> obscure protocols on obscure systems that were killed off by their
> vendors (if the vendors even exist anymore) a decade or more ago, and no
> source code or upgrade path is available.
> The "enterprise" networking world is just as ugly as, if not uglier
> than, the consumer one.

I haven't worked much on the commercial private internets, but I did
work for someone who connected on the back end into numerous telco
cellphone IP data networks.

For all of those who argue that these applications should use 1918
space, I give you those networks, where at one point I counted
literally 8 different 10.200.x/16 nets I could talk to at different
partners (scarily enough, 2 of those were "the same company"...).  And
hundreds and hundreds of other space conflicts.

Yes, you can NAT all of that, but if you get network issues where you
need to know the phone end address and do end to end debugging on
stuff, there are no curse words strong enough in the English language.

-george william herbert
george.herbert at

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