nanog mailing list archives
Re: Please, talk me down.
From: Mark Andrews <marka () isc org>
Date: Wed, 17 Oct 2012 16:21:44 +1100
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
Current thread:
- Please, talk me down. Joseph Anthony Pasquale Holsten (Oct 16)
- Re: Please, talk me down. Mikael Abrahamsson (Oct 16)
- Re: Please, talk me down. Mike Lyon (Oct 16)
- Re: Please, talk me down. Jima (Oct 16)
- Re: Please, talk me down. Karl Auer (Oct 16)
- Re: Please, talk me down. Randy Bush (Oct 16)
- Re: Please, talk me down. Jimmy Hess (Oct 17)
- Re: Please, talk me down. Leen Besselink (Oct 21)
- Re: Please, talk me down. Jimmy Hess (Oct 17)
- Re: Please, talk me down. Mark Andrews (Oct 16)
- Re: Please, talk me down. Octavio Alvarez (Oct 16)
- Re: Please, talk me down. Antonio Querubin (Oct 16)
- Re: Please, talk me down. JP Viljoen (Oct 16)
- Re: Please, talk me down. John Levine (Oct 17)
- Re: Please, talk me down. Nicolai (Oct 17)
- Re: Please, talk me down. Jay Mitchell (Oct 21)
- Re: Please, talk me down. Jay Mitchell (Oct 21)
- Re: Please, talk me down. Nicolai (Oct 21)
- RE: Please, talk me down. Keith Medcalf (Oct 21)
- Re: Please, talk me down. Suresh Ramasubramanian (Oct 21)