viewing dns server cache 2

[grnfvr]

i know how to view ther cached dns records on the client. how do you view the dns records cached by the dns server itself? the same way? ipconfig /displaydns I wouldn't think so because then you would actually be viewing the client dns cache on the server, right?

 

[FilthPig]

Open DNS from Administrative Tools, expand your server and there should be a folder there for Cached Lookups. If you don't see it, enable the Advanced view by clicking on View -> Advanced. Marc Creviere

 

[GlenJohnson]

Did what you said, and it's great. Only problem is I see some of my users have been naughty. Can I manually delete a sigle cache, or is it better to flush dns and let the table rebuild? Glen A. Johnson
Microsoft Certified Professional
gjohn76351@msn.com
"Accident is the name of the greatest of all inventors."
Mark Twain (1835-1910), U.S. author.

 

[FilthPig]

Yeah, you should be able to right-click and delete items in there. Marc Creviere

 

[jpeachman]

Better yet, you can use the info from the cache to create your own DNS entries for the sites your "naughty" users frequent. If you do that, they won't be able to go back there unless they enter the actual IP address in the browser! E.g., if you want to block users from going to xxx.com, you can create a DNS entry for xxx.com, and don't bother to fill in the IP address. Once you delete the entry from the cache, future DNS queries for xxx.com will return an invalid IP address to the client, and users will get an error message.

Joe

 

[grnfvr]

great idea jpeachman, but that will only work if the user keeps repeatedly trying to go to the site because otherwise the record will become discarded and then the dns server will go out and get the correct dns record from the authoratative dn server for that domain

 

[jpeachman]

Actually, no. What I've done is add a new zone for each site or domain I want to block. While the only real domain for which our server is authoritative is our own, when I add other zones (which aren't properly ours) to our DNS server, it happily sends users to nowhere indefinitely for those sites. Unlike a cache entry, which has a time-to-live and is then discarded if not refreshed (and which I don't think you can edit anyway), these records are permanent. I actually have this in practice at a public school where I'm network admin, and it works fine!

Joe

 

[grnfvr]

thanks, that makes much more sense, just be sure you boss doesnt think your hosting those XXX sites, lol