In message <2801F5F8-B8E2-4A9F-9A89-02D7783CCDA7@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: marka@isc.org