How to check the network for caching DNS?

Question

PowerShell

Good afternoon.
How can I check if there is a caching server in the local network of the enterprise? I understand that I need to somehow make a request using nslookup to the site, and to the address of the ns server, but I don’t understand what I should get and compare.

Answer 1

on the client computer...is there caching or not.

There is always. To reset it, use ipconfig /flushdns.
Or do you want

I don’t understand what I should get and compare

find out that the DNS IP belongs to the same network as the client? So it will be almost always. Since very, very rarely, almost never the client will be connected to the backbone directly.

Answer 2

In general, if it is necessary to determine whether the TTL changes on the cached server (I assume that it is a rare case), then 2 DNS requests are needed to obtain additional information about the TTL of the element with a pause of 1-10 seconds - then you will see if the TTL has changed or not.