On Jul 4, 2011, at 8:23 PM, John R. Levine wrote: >> Reverse IPv6 caches well. You just can't pre-populate servers with PTR >> records for all 2^64 ptr records in a normal IPv6 subnet. You need to >> use tools that add records for nodes that actually exist. Those tools >> are a decade old now. > > Over in e-mail land, we've been pondering the behavior of spammers, who will > likely hop to a different IPv6 address for every spam. If you do rDNS > lookups, your cache will fill up with useless entries, maybe PTR, maybe > NXDOMAIN, it hardly matters. DNSBLs and DNSWLs, if done the same way as they > are in IPv4, have the same problem. These issues are well known in the mail > ops community, where it's now the standard advice not to try rDNS lookups on > incoming IPv6 mail.
Yes, but rDNS PTR lookups always have been pretty much meaningless anyway, and will only get worse in IPv4 due to LSN. Keith _______________________________________________ Ietf mailing list [email protected] https://www.ietf.org/mailman/listinfo/ietf
