Forum Discussion
Windows DNS client - delay with reverse lookup
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 - th...
Hi,
I was wondering did you receive any feedback or find the reason why reverse DNS is slow. I see the exact same behavior at a customer, did also a Wireshark trace and see the DNS reverse request, immediate answer from DNS server and seconds nothing until de reply starts of the ping.
I've seen also this behavior:
- reverse lookup in the same subnet = slow -> in this case I see ARP request just before the reply of the ping but delay between DNS reply and ARP
- reverse lookup in another subnet = fast -> in this case no ARP request because it is sent to the default gateway and that is already in his local ARP table. see immediately after the DNS response ICMP packets
- have it both on Windows 2012 R2 and Windows 2016, not on Windows 2008 R2
- don't have it on non-domain joined servers (so in workgroup) or at least cannot simulate it
For simulation I just use ping -a x.x.x.x
If you have more info let me know?
Thx,
Pete
I was wondering did you receive any feedback or find the reason why reverse DNS is slow. I see the exact same behavior at a customer, did also a Wireshark trace and see the DNS reverse request, immediate answer from DNS server and seconds nothing until de reply starts of the ping.
I've seen also this behavior:
- reverse lookup in the same subnet = slow -> in this case I see ARP request just before the reply of the ping but delay between DNS reply and ARP
- reverse lookup in another subnet = fast -> in this case no ARP request because it is sent to the default gateway and that is already in his local ARP table. see immediately after the DNS response ICMP packets
- have it both on Windows 2012 R2 and Windows 2016, not on Windows 2008 R2
- don't have it on non-domain joined servers (so in workgroup) or at least cannot simulate it
For simulation I just use ping -a x.x.x.x
If you have more info let me know?
Thx,
Pete