Google wants to be your Internet

michael.dillon at michael.dillon at
Wed Jan 24 13:48:04 UTC 2007

> The problem is that you can't be sure that if you use RFC1918 
> today you won't be bitten by it's non-uniqueness property in 
> the future. When you're asked to diagnose a fault with a 
> device with the IP address, and you've got an 
> unknown number of candidate devices using that address, you 
> really start to see the value in having world wide unique, 
> but not necessarily publically visible addressing.

A lot of people who implemented RFC 1918 addressing in the 
past didn't actually read RFC 1918. They just heard the mantra
of address conservation and learned that RFC 1918 defined something
called "private" addresses. Then, without reading the RFC, they
made assumptions in interpreting the meaning of "private". Now,
many of those people or their successors have been bit hard by
problems created by using RFC 1918 addresses in networks which 
are not really private at all, i.e. wholly unconnected from other
IP networks. Those people now see the benefits of using truly
globally unique registered addresses.

The whole address conservation mantra has turned out to be a lot
of smoke and mirrors anyway. The dotcom collapse followed by the
telecom collapse shows that it was a sham argument based on the
ridiculous theory that exponential growth of the network was 
really sustainable. Now we live in a time where there is no
shortage of IP addresses. Even IPv4 addresses are not guaranteed
to ever run out as IPv6 begins to be used for some of the drivers
of network growth. 

IPv6 makes NAT obsolete because IPv6 firewalls can provide all
the useful features of IPv4 NAT without any of the downsides.

--Michael Dillon

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