On Nov 30, 2011, at 9:14 PM 11/30/11, Pete Resnick wrote: > Daryl, > > The problem described in the draft is that CPEs use 1918 space *and that many > of them can't deal with the fact that there might be addresses on the outside > interface that are the same as on the inside interface*. The claim was made > by Randy, among others, that only 192.168/16 space was used by such > unintelligent CPEs. I believe I have seen the claim that 10/8 space is also > used in unintelligent equipment that can't deal with identical addresses > inside and outside.
Another suggestion was the use of 10.64.0.0/10, with the argument that some devices may use 10.0.0.0 but those devices tend to start numbering with 10.0.0.0/24 or 10.0.1.0/24 and none would use addresses in 10.64.0.0/10. Is there evidence that there are deployments today of devices that use addresses in 10.64.0.0/10? - Ralph > Is there reason to believe that within the ISP network / back-office etc. > that there is equipment that can't deal with 17.16/12 space being on both the > inside and outside? I haven't seen anyone make that specific claim. > > If we know that 172.16/12 used both inside and outside will break a > significant amount of sites that CGNs will be used with, we can ignore this > argument. But if not, then let's rewrite the document to say that CGNs should > use 172.16/12 and that any device that wants to use 172.16/12 needs the > ability to deal with identical addresses on the inside and the outside > interface. Of course, all equipment should have always been able to deal with > identical addresses inside and outside for all 1918 addresses anyway. But if > we think the impact of using 172.16/12 for this purpose will cause minimal > harm, then there's no compelling reason to allocate new space for this > purpose. > > pr > > On 11/30/11 3:04 PM, Daryl Tanner wrote: >> It's not just about the CPE devices and customer LANs. >> >> Address conflicts are also going to happen within the ISP network / >> back-office etc. 172.16.0.0/12 is used there. >> >> >> Daryl >> >> >> On 30 November 2011 20:52, Brian E Carpenter <[email protected]> >> wrote: >> On 2011-12-01 09:28, Chris Grundemann wrote: >> ... >> > It is more conservative to share a common pool. >> >> It suddenly occurs to me that I don't recall any serious analysis >> of using 172.16.0.0/12 for this. It is a large chunk of space >> (a million addresses) and as far as I know it is not used by default >> in any common CPE devices, which tend to use the other RFC 1918 blocks. >> >> I realise that ISPs with more than a million customers would have to >> re-use this space, whereas a /10 would only bring this problem above 4M >> customers, but at that scale there would be multiple CGN monsters anyway. >> >> Sorry to bring this up on the eve of the telechat. > > -- > Pete Resnick > <http://www.qualcomm.com/~presnick/> > > Qualcomm Incorporated - Direct phone: (858)651-4478, Fax: (858)651-1102 > _______________________________________________ Ietf mailing list [email protected] https://www.ietf.org/mailman/listinfo/ietf
