I have a network set up, and recently replaced our two Windows Server 2008 R2 domain controllers with two Windows Server 2012 R2 domain controllers. Both are VMs, each on a different physical machine. Both of my domain controllers have DNS server enabled, and both are configured to use five different external Forwarders (and to use root hints if no forwarders are available).
Since the upgrade, we now experience DNS timeouts twice a day (these timeouts occur on both the dns server itself, and clients. At the moment the pattern seems to be at around 7:30am the dns timeouts happen, and then again at the end of the day. A reboot of the main primary DNS server resolves the issue.
I have no idea why this is happening, and would like to reach out to the community for help!
nslookup with d2 param when everything is working (partial results):
SendRequest(), len 46 HEADER: opcode = QUERY, id = 4, rcode = NOERROR header flags: query, want recursion questions = 1, answers = 0, authority records = 0, additional = 0
QUESTIONS:
www.bbc.co.uk.electrum.co.uk, type = A, class = IN
------------
Got answer (108 bytes): HEADER: opcode = QUERY, id = 4, rcode = NXDOMAIN header flags: response, want recursion, recursion avail. questions = 1, answers = 0, authority records = 1, additional = 0
QUESTIONS:
www.bbc.co.uk.electrum.co.uk, type = A, class = IN
AUTHORITY RECORDS:
-> electrum.co.uk
type = SOA, class = IN, dlen = 50
ttl = 837 (13 mins 57 secs)
primary name server = ns0.lumison.net
responsible mail addr = hostmaster.lumison.net
serial = 2013112000
refresh = 28800 (8 hours)
retry = 7200 (2 hours)
expire = 604800 (7 days)
default TTL = 7200 (2 hours)
And again, but this time when it's not working (partial results):
SendRequest(), len 46 HEADER: opcode = QUERY, id = 4, rcode = NOERROR header flags: query, want recursion questions = 1, answers = 0, authority records = 0, additional = 0
QUESTIONS:
www.bbc.co.uk.electrum.co.uk, type = A, class = IN
DNS request timed out. timeout was 2 seconds. timeout (2 secs) SendRequest failed
Any help is greatly appreciated!
EDIT:
It seems that doing a tracert 8.8.8.8 from the domain controller FIXES the issue, until it happens again 24 hours later.