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The idea of solving the problem by reclaiming IPv4 addresses was considered, but the math doesn't work:

Now, average daily assignment rates have been running at above 10 /8s per year, for 2010, and approached 15 /8s towards the end. This means any reclamation effort has to recover at least 15 /8s per year just to break even on 2010’s growth. That’s 5.9% of the total IPv4 address space, or 6.8% of the assignable address space.

Looking at the /8 blocks assigned to organizations other than regional NICs, there are 40 of them. So even if we could persuade all those organizations to give up their /8s, and even if we could organize it all quickly enough, the best we could do would be to put off the problem for 3 more years.

In addition, reclaiming IPv4 addresses is far more expensive than rolling out IPv6, and it's hard enough to persuade companies that they need to roll out IPv6.

And the calculation for class B allocations is even worse, because you have to deal with a lot more organizations; the cost is higher for far lower returns.

Well, let's agree to disagree to on point 1. I do agree with you though, IPv6 will be less fragmented than IPv4, though I do also think there are processes besides de-aggregation in the face of address space pressures that cause fragmentation, and I think IPv6 will face those pressures too. IPv6 needs to be seriously used first, and it may also require time.

Next, IPv6 addresses are of course 4 times larger than IPv4 addresses. Even if your IPv6 routing table has 5 times fewer entries, you're not getting a 5 times saving in memory. You're only getting a 5/4 times saving or tables that are 80% of the IPv4 - nowhere near as dramatic.

I'd contend 2 is the real underlying problem. Routing tables growing with the size of the network, in terms of # of entries - even if not at all fragmented. In terms of overall size, it's O(NlogN), however given we're using a fixed-length address label, that logN factor makes itself known in quite big jumps, as illustrated in the previous paragraph. That 20% saving will be eaten extremely quickly if the Internet keeps growing at super-linear pace. Given so much of the world's population isn't yet online, there's every reason to think the Internet still has plenty left to grow. Even in the developed world, there's no reason to think the amount of address space used per person will not grow dramatically. The amount of network enabled devices each of us own just keeps growing. The "Internet of Things" is the current buzzword, looking at network-enabling many small devices. Granted, that won't directly increase pressure on routable bits where a site upgrades to v6 from an existing v4 connection, e.g. a person's home, however there are surely many use-cases that involve new distinct locations coming online (e.g. cars?).

IPv6 is just neutral on the routing scalability question. Reduced fragmentation seems a trivial saving, at least to me.

Worse, it is possible that IPv6 is actually too small to be able to solve routing scalability.

Dear Slashdot,

You've posted a story from the Dailymail that has the form "EU wants to do outrageous thing!". The Dailymail has a long track record of:

a) Hating the EU.

b) Printing utter falsehoods about supposed plans "the EU" has, at least in their headlines and leading text.

E.g., a previous instance, which I complained to the PCC about (who turn out to be toothless and/or cowards): http://paul.jakma.org/2011/11/... .

Please do not feed the Dailymail troll.

See:

http://hibernia.jakma.org/~paul/rc.iprules

For a script that does something similar to what you want, policy routing to route based on source IP. It should be easy enough to add an additional 'firewall mark' field to the table and policy route based on that (i'm on holiday, otherwise i might have done that for you). The listed "intranets" will use the main table.

Basically, all you need is:

1. create a table for each policy (edit /etc/iproute2/rt_realms)

2. use iptables to add arbitrary 'fwmarks' to incoming packets based on whatever criteria you have

3. use the 'ip rule' command to direct routing for packets with specific fwmarks to specific routing tables.

4. direct other traffic to the default 'main' table.

Finally, see the Linux Advanced Routing & Traffic Control site for further information.

Oh even better, Slashdot run ads for bulk-mailers and spam, sorry, "opt-in" address list resellers. Kind of ironic considering slashdot's editorial stance on spam: "Spam is evil and bad", - unless of course its money they send you rather than spam...

Oh even better, Slashdot run ads for bulk-mailers and spam, sorry, "opt-in" address list resellers. Kind of ironic considering slashdot's editorial stance on spam: "Spam is evil and bad", - unless of course its money they send you rather than spam...

Your email takes too much effort to figure out paul@jakma.org - Did I get it correct?