DNS host file

mr2nut

Having a bit of a debate at work about this. Now most networks these days have DNS integrated into active directory, so i'm guessing the local host file isn't used in this case?

But if you decide to implement a domain without integrated DNS, do all client PCs rely on local host files on each machine and automatically add entries to the host file? Also, when you do a flushdns, does it remove entries from the host file or is this a static file and the cached DNS records stored somewhere else?

BeaverC32

Flushdns = remove hostname to IP mappings from cache (file is left untouched).

Order of hostname resolution is:
1) The client checks to see if the name queried is its own.
2) The client then searches a local Hosts file, a list of IP address and names stored on the local computer.
3) Domain Name System (DNS) servers are queried.
4) If the name is still not resolved, NetBIOS name resolution sequence is used as a backup. This order can be changed by configuring the NetBIOS node type of the client.

(Source:http://support.microsoft.com/kb/172218)

Mishra

Nothing automatically adds entries to the host file.

I know this wasn't really a part of your question but if you wanted to have a DNS like infrastructure you could edit the host file for every machine in the domain through GPO.

BeaverC answered the rest of your questions.

BeaverC32

And not to sound like an arse, but this is all covered thoroughly in the 70-291 exam, which you have passed.

blargoe

If you don't have ad-integrated dns, you can still have a dedicated dns server with dns data, it just doesn't get propegated using active directory.

Hosts files are almost never used anymore... you should avoid using them unless it's a last option.

You need a primer on DNS... there's so much more to it than what Microsoft says you need to know for their flavor of DNS

http://en.wikipedia.org/wiki/Domain_name_system

mr2nut

BeaverC32 wrote:

And not to sound like an arse, but this is all covered thoroughly in the 70-291 exam, which you have passed.

And certain things that you dont use daily you can sometimes overlook. Sorry for not having a brain like a book

Megadeth4168

mr2nut wrote:

BeaverC32 wrote:

And not to sound like an arse, but this is all covered thoroughly in the 70-291 exam, which you have passed.

And certain things that you dont use daily you can sometimes overlook. Sorry for not having a brain like a book

I think we all understand that. I myself am guilty of that. There are a lot of MS technologies that we don't use at work that I am certified to use. A bit of refreshing on the topic should be all I need to get going if we do implement those technologies but I wouldn't know what to do without some documentation.

It's hard to keep refreshed on everything.

I think the point that BeaverC32 was trying to make is that the 291 is an exam that focuses heavily on DNS and the question being asked is pretty elementary as far as DNS goes. Again, I understand you may not use the technology everyday, I'm just trying to look at it from both points of view.

BeaverC32

mr2nut you forgot to say thank you

Ahriakin

Have fun manually entering all of those Service records for your clients to even find the DCs .
It's just not really workable in this day and age. The only real use I can think of for a hosts file these days is manually blackholing domains.

HeroPsycho

There are times you need to use host files. As a good example, I've used host files on ISA servers to point to the "real" Exchange front end array, because DNS is pointing to this ISA array that's publishing it. Therefore, if ISA used DNS to resolve the name for the publishing rule, ISA would grab it's own butt, which everyone knows isn't nearly as fun as grabbing someone else's. :P

BeaverC32

Ahriakin wrote:

Have fun manually entering all of those Service records for your clients to even find the DCs .
It's just not really workable in this day and age. The only real use I can think of for a hosts file these days is manually blackholing domains.

SpyBot's hostfile feature is nice -- with a simple click of a button, there are hundreds of entries added that map malware sites to localhost.

mr2nut

BeaverC32 wrote:

mr2nut you forgot to say thank you

Cheers for the first post though, aye

Kaminsky

Not quite sure why but integrated DNS to AD makes me very worried for the future for some reason knowing how mickey mouse rapidly becomes the standard in later years.

I must be getting old.... In 100 years I'm sure my great great grandchildren will be laughing about things like this.


Speaking of DNS though, I'm still pi$$ed that you yanks could pull the plug on the internet at anytime........... for about 1/2 hour of course ......