On Wed, 2008-12-31 at 11:57 -0500, William Herrin wrote: > On Wed, Dec 31, 2008 at 11:07 AM, RJ Atkinson <[email protected]> > wrote: > > I agree with Steve Blake that a NAT-oriented approach, > > which I gather is category "H", ought to get serious consideration. > > Ran, > > Would you care to describe a NAT category which credibly addresses the > routing scalability problem in a manner not already encompassed in > widely deployed NAT systems?
That's the point: widely deployed NAT (as it exists today) is a do-nothing strategy from an interdomain routing point-of-view. > I have no intention of adding: > > Strategy H: We should use NAT! > Major criticisms: We should use NAT to do what exactly? Allow sites to have stable internal addressing without putting pressure on interdomain routing scalability from additional PA prefixes. PROS: - Unilateral deployment incentives: no need for any global coordination, or involvement by the providers. - Widely tested, mature technology (for IPv4, at least). CONS: - Does not provide session survivability in the event of uplink failover (at least not with current IPv4/IPv6 and transport protocols). - N:1 address multiplexing (v4 NAT) makes it difficult to support inbound connections. v6 NAT could be better in this respect. - Breaks certain classes of applications (i.e., those that depend on address referrals). In some environments this is considered a feature, not a bug. All of these cons could be mitigated by evolution of IP and/or transport protocols. As long as these enhancements support backwards compatibility, they could be incrementally deployed. Many have already been discussed in RRG. PS. Nobody despises NAT more than I do. Regards, // Steve _______________________________________________ rrg mailing list [email protected] https://www.irtf.org/mailman/listinfo/rrg
