Where does the DNS record go?

Question

Although I was able to "ping by IP," I was unable to "ping by name" a freshly installed Windows 2008 R2 VM. I fixed the problem by temporarily activating "network discovery" rules on the W2k8 VM, which allowed the host to discover the name. Afterward, I turned network discovery rules back off again.

This activity is on my home "workgroup" network.

After the discovery rules were disabled the host continued to "know" the guest by its name, even though network discovery was turned off. I expected this, because I expected it would cache the name. My question is: where does it cache that information? What is the simplest way to read the full directory of machine-name entries that the host has cached?

How would I manually remove the entry if I wanted? How would I manually add an entry to that list if I wanted?

Answer 1

This is because without network discovery, your server cannot use broadcasts to resolve hosts.

In a Microsoft domain, they use a local DNS server, which all the local Microsoft Windows computers register their host name with with in DNS, so that is how they find each other.

If you are not running a Domain, or internal DNS server, you are turning off the only way they can find each other unless you add entries to the HOSTS file. The cache you are talking about is very volatile, and gets flushed often (almost certainly when turning network discovery on and off). If you want something permanent, short of running the DNS service on that server, use the HOSTS file located here: C:\Windows\System32\drivers\etc\HOSTS (it is read only, so uncheck it before you make changes).

Answer 2

To clear the resolver caches, use:

• ipconfig /flushdns for DNS

• nbtstat -R for NetBIOS

• unknown for LLMNR