Apr 15 2018 01:25 PM
Hello
I have windows 2012 server, which is in MS cluster. In TCP/IP protocol 3 dns servers are configured (this server works as dns client)
And there is problem with reverse lookup requests - there is additional delay about 4 seconds.
Some facts:
1. DNS servers works fine. There is no delay in response (captured packets on network with Wireshark, response comes within mseconds. Exactly these DNS servers are also used on other windows machines and there is no problem with them.
2. nslookup works fine. There is no delay and correct response is returned.
(but nslookup bypass dns client and queries DNS server directly)
3. ping -a <ip-address> gives delay for about 4 seconds.
4. I do not see any NetBIOS or WINS requests from this computer in Wireshark.
5. If I add corresponding entries into hosts file - then ping -a <ip-address> works without delay.
6. Normal dns queries via dns client (ping <hostname>) works fine, there is no any additional delay.
I cannot blame DNS servers - they seems to work fine without any problem.
The problem seems to be in the local dns client, but I am out of ideas what else can I check.
Below captured traffic in Wireshark, and results of "nslookup -debug <ip-address>" command.
If you have any idea where problem could be - you are more than welcome :-).
C:\Users\admin\Documents>nslookup -debug 10.198.126.28
------------
Got answer:
HEADER:
opcode = QUERY, id = 1, rcode = NOERROR
header flags: response, auth. answer, want recursion, recursion avail.
questions = 1, answers = 1, authority records = 0, additional = 0
QUESTIONS:
199.199.199.10.in-addr.arpa, type = PTR, class = IN
ANSWERS:
-> 199.199.199.10.in-addr.arpa
name = lbaxxxxx.xxx.xx
ttl = 86400 (1 day)
------------
Server: lbaxxxxx.xxx.xx
Address: 10.199.199.199
------------
Got answer:
HEADER:
opcode = QUERY, id = 2, rcode = NOERROR
header flags: response, auth. answer, want recursion, recursion avail.
questions = 1, answers = 1, authority records = 0, additional = 0
QUESTIONS:
28.126.198.10.in-addr.arpa, type = PTR, class = IN
ANSWERS:
-> 28.126.198.10.in-addr.arpa
name = SVMXXXX.xxx.xx
ttl = 86400 (1 day)
------------
Name: SVMXXXX.xxx.xx
Address: 10.198.126.28
Mar 01 2019 04:35 AM