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Great! Now we have to collect routing policies from

thousands of small LIRs

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while still have to deal with thousands of small prefixes.

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So? There is no difference between thousands of PI prefixes and "thousands of small LIRs", except that the latter actually have to *pay* for what they cause.

Right. Strong ACK on this.

So what do the small LIRs solve ?

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And if the major ISPs stop listening to the more specfic routes then even using the address from PI space won't work (unless you are big enough).

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Yes. This is what it's all about. Small PI space really hurts people.

Yep. And therefore these "small" PI stuff should be cleaned up. The User itself can use it internally and could get a /24 routed from PA space.

But it is really not the optimum solution, as it waste's ip address space. And we have enough RFC1918 space...

This is not enough but I am going to go with this solution. Then we will ask you to assign only aggregatable address( to a /20 of course) to your customer if they are going to use CW as a backup ISP. You will happily reassign their addresses once they got a link from CW, right ? If you don't then what ? CW will have to leak your /24 to the world but it is you causing it. On the other hand, if our customer ask you to be the backup ISP, we will ask them to change all their DNS records, all their host tables, all their static IP configs to change to the new aggregatable block. If they think this is too much hassle, we will advice them not to use your service because you don't accept /24 multi-homed customer. This sounds realistic enough ?

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Letting "the whole world" see a /16 (from the upstream) and the direct peers a /24 (or whatever) means global routing will just work fine (over the upstream's PA block) and and IX routing will also work just fine (using the more specific).

right, but is it generally used ? I see a lot of /24 out of the same block from a /16 announced space globally (AS5511 for example)

Because it is not the solution to the real world, that's why people can only talk about it but not really to enforce it. Ping Lu Cable & Wireless USA Network Tools and Analysis Group W: +1-703-292-2359 E: plu@cw.net