My team has a server pointing at the DNS supplied by Active Directory to ensure that it is able to reach any hosts managed by the domain. Unfortunately, my team also needs to run
dig +trace frequently and we sporadically get strange results. I am a DNS admin but not a domain admin, but the team responsible for these servers isn't sure what is going on here either.
The problem seems to have shifted around between OS upgrades, but it's hard to say whether that's a characteristic of the OS version or other settings being changed during the upgrade process.
- When the upstream servers were Windows Server 2003, the first step of
. IN NSfrom the first entry in
/etc/resolv.conf) would occasionally return 0 byte responses.
- When the upstream servers were upgraded to Windows Server 2012, the zero byte response problem went away but was replaced with an issue where we would sporadically get the list of forwarders configured on the DNS server.
Example of the second problem:
$ dig +trace -x 220.127.116.11 ; <<>> DiG 9.8.2 <<>> +trace -x 18.104.22.168 ;; global options: +cmd . 3600 IN NS dns2.ad.example.com. . 3600 IN NS dns1.ad.example.com. ;; Received 102 bytes from 192.0.2.11#53(192.0.2.11) in 22 ms 1.in-addr.arpa. 84981 IN NS ns1.apnic.net. 1.in-addr.arpa. 84981 IN NS tinnie.arin.net. 1.in-addr.arpa. 84981 IN NS sec1.authdns.ripe.net. 1.in-addr.arpa. 84981 IN NS ns2.lacnic.net. 1.in-addr.arpa. 84981 IN NS ns3.apnic.net. 1.in-addr.arpa. 84981 IN NS apnic1.dnsnode.net. 1.in-addr.arpa. 84981 IN NS ns4.apnic.net. ;; Received 507 bytes from 192.0.2.228#53(192.0.2.228) in 45 ms 1.in-addr.arpa. 172800 IN SOA ns1.apnic.net. read-txt-record-of-zone-first-dns-admin.apnic.net. 4827 7200 1800 604800 172800 ;; Received 127 bytes from 22.214.171.124#53(126.96.36.199) in 167 ms
In most cases this isn't a problem, but it will cause
dig +trace to follow the wrong path if we are tracing within a domain that AD has an internal view for.
dig +trace losing its mind? And why do we seem to be the only ones complaining?