"Geo" == Geo <georger@getinfo.net> writes:
Geo> Got something really weird going on and I need a bit of help Geo> from someone who is really good with dns. Geo> Domain elby.ch Geo> seems to resolve from some DNS servers but not from others. Can Geo> you see anything that might break dns resolution for this Geo> domain? Yes, you've got _way_ too many levels of referrals before any glue records show up. The chain looks something like this: .ch servers return referral elby.ch -> ns{1,2}.elbyns.de with no glue. .de servers return referral elbyns.de -> ns{1,2}.aixns.de with no glue. .de servers return referral aixns.de -> ns0.ns0.de,ns2.ns2.de with no glue. .de servers return referral ns0.de/ns2.de -> ns*.denoc.de with glue. When I tried it with the squish.net dns checker (turn on "show resolving of referrals" to see the awful details of the referral chain) I got at least one query timeout, so the results were: 10.7% of queries will end in failure at 62.116.163.62 (ns2.ns2.de) - failed to resolve ns2.elbyns.de due to 62.116.163.62 - failed to resolve ns1.aixns.de due to 62.116.163.62 - query timed out 10.7% of queries will end in failure at 62.116.163.62 (ns2.ns2.de) - failed to resolve ns1.elbyns.de due to 62.116.163.62 - failed to resolve ns1.aixns.de due to 62.116.163.62 - query timed out 39.3% of queries will be returned by 62.116.130.76 (ns1.elbyns.de) elby.ch. 86400 IN A 213.130.59.30 39.3% of queries will be returned by 62.116.162.15 (ns2.elbyns.de) elby.ch. 86400 IN A 213.130.59.30 But the squish.net checker has no limit on referrals - many resolvers, especially older BIND, will just time out chasing the referrals unless it already has them cached. -- Andrew, Supernews