In message <2801f5f8-b8e2-4a9f-9a89-02d7783cc...@josephholsten.com>, Joseph Ant hony Pasquale Holsten writes: > I want to like IPv6. I do. But I'm seriously considering turning off > IPv6 support from our servers. > > First off, I'm using djbdns internally and it doesn't support AAAA > records. So we really aren't using it internally.
djbdns doesn't support lots of things. > But today I noticed that we have a lot of traffic to our DNS cache, and > started to investigate. Turns out that every DNS request would start > with one for the AAAA record. Ah, no luck. Maybe you forgot the search > domain? Let's retry that DNS request with that tacked on. Failed again? > Meanwhile, lets simultaneously try for the AA record then. Repeat. It looks like your getaddrinfo implementation is a searching for AAAA records and then searching for A records. With a A record for name2 you get a query path like this. e.g. name1 AAAA -> NXDOMAIN name2 AAAA -> NODATA name3 AAAA -> NXDOMAIN name1 A -> NXDOMAIN name2 A -> DATA You could ask you vendor to implement a alternating search strategy. e.g. name1 AAAA -> NXDOMAIN name1 A -> NXDOMAIN name2 AAAA -> NODATA name2 A -> DATA Additionally you could get your vendor skip the A lookup on NXDOMAIN from AAAA. e.g. name1 AAAA -> NXDOMAIN name2 AAAA -> NODATA name2 A -> DATA > I'm _this_ close to turning IPv6 off entirely. Anyone want to talk me > off this ledge? > -- > http://josephholsten.com > -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org