DNS issues? Unable to view servers by hostname from clients

[klop]

Hi, I'm in the middle of setting up wpad and have found there are some issues with our dns settings.

 

Server03 has IIS 7 installed.

On server03 I can see the IIS default page using http://server03 or ip address

On server02 I am able to see IIS default page using http://server03 or ip address

 

Both servers are DCs.

server02 is DNS

 

Clients are only able to view IIS default page by ip address, http://server03 does not work.

[edit]Turns out some clients will connect via ie using hostname - whilst others still do not. All so far are able to see our spiceworks front login page using that servers hostname (but I've not tried every client yet!)[/edit]

 

I'm guessing there are issues with DNS - DNS has never, ever been my thing!

 

Appreciate any advice, thanks

Edited November 8, 2013 by klop

[pughburt]

Are the clients DHCP? Has DNS been authorized? Have you assigned the correct DNS in DHCP?

[pantscat]

Hi @klop

 

Do your clients get their IP addresses by DHCP? or do you assign them manually?

If it's the former - check your DHCP scope to see what DNS servers, if any, you have specified.

 

If that all looks good, the next step would be to go to a client machine and open a command prompt and check name resolution.

 

1. Try "ping server03" and see what IP address it tries to ping (if any)

2. Try "nslookup server03" - what result do you get?

 

Let me know how you get on!

[Jawloms]

Might be worth doing an ipconfig /all on a client and just making sure its DNS server is the IP address of server02.

[klop]

Interestingly (perhaps!) I've found some devices are able to see http://server03

 

With one device that wouldn't see it by hostname after running ipconfig /flushdns it did - and now does connect

However other devices I have tried using ipconfig /flushdns with haven't worked.

 

What a mess huh!

[klop]

@pughburt Yes, DHCP and yes the DNS is correct

 

@pantscat DHCP

If i ping server03 from a client that cannot view http://server03 the ping replies. So I guess something is resolving the name into the correct address - just not in the browser?

 

I ran nslookup, results are;

 

Server: server02.xxx.local

Address: 10.x.x.4

 

Name: server03.xxx.local

Address: 10.x.x.5

 

All above xxx details are correct just thought I should x them out

Only thing i guess is server02 does have two addresses, but the one listed was correct

 

@Jawloms ipconfig shows correct DNS DHCP etc

 

 

Our DNS server (server02) has two IPs .3 and .4

Could that cause any problems - should i disable one?

 

I've also tried our spiceworks server.

Laptop client that cannot see server02 CAN see our spiceworks server by hostname in the browser - does this shed any light? If anything I thought it made it a tad more confusing!

 

 

Thanks for advice so far

Edited November 8, 2013 by klop

[jinnantonnixx]

Only thing i guess is server02 does have two addresses, but the one listed was correct

 

Our DNS server (server02) has two IPs .3 and .4

Could that cause any problems - should i disable one?

 

 

I'm going to guess that one of those addresses is not reachable from the clients. Delete the unreachable entry from DNS and see what happens.

[jinnantonnixx]

Also check your DNS suffix

 

Run NSLOOKUP (press return)

You're in interactive mode now.

Type: set debug

and now enter some names to be resolved.

There'll be a whole screen full of stuff, I've often found that DNS suffix goes wrong, where it's not appending it to your domain names.

Also try typing the FQDN of the server

[klop]

I'm going to guess that one of those addresses is not reachable from the clients. Delete the unreachable entry from DNS and see what happens.

 

Damn!! Thought you may have found a nice simple fix then!

 

I ping server02 (our dns server) from two clients, one working and one not and was eager to see they were both using different addresses for server02.

I've deleted .3 from dns as one client was using .4 and working fine.

Rebooted the laptop that wasn't connecting and it's still not working but is now using .4 which works on the other machine

[klop]

Also check your DNS suffix

 

Run NSLOOKUP (press return)

You're in interactive mode now.

Type: set debug

and now enter some names to be resolved.

There'll be a whole screen full of stuff, I've often found that DNS suffix goes wrong, where it's not appending it to your domain names.

Also try typing the FQDN of the server

 

thanks, there's a lot to look through.

using full fqdn shows a lot more

 

anything in particular i should be looking for?

 

thanks again

[klop]

Also check your DNS suffix

 

Run NSLOOKUP (press return)

You're in interactive mode now.

Type: set debug

and now enter some names to be resolved.

There'll be a whole screen full of stuff, I've often found that DNS suffix goes wrong, where it's not appending it to your domain names.

Also try typing the FQDN of the server

 

Ok one thing that looks iffy - might not be though?

 

when i use server02 all looks fine but when i use FQDN there is one error?

 

under the header there is NXDOMAIN where all others have NOERROR

The noticeable thing is under Questions it has the name as server02.domainname.local.domainname.local

 

All others are server02.domainname.local

 

Thanks - think you've given me a lead

Edited November 8, 2013 by klop

[klop]

just tried this on a client that can see the page by name and there are no errors - look like a good place to start - thanks again

 

Ok this is in fact wrong - I must have read it incorrectly. I get the NXDOMAIN and mydomain.local.mydomain.local double suffix when using a FQDN on any client whether it can see server03 hostname or not. Also I get the NXDOMAIN for all machines I lookup and not just server03

[jinnantonnixx]

You'll see NXDOMAIN messages when in debug mode and not using FQDN. This is because NSLOOKUP pastes in your DNS suffix(es) to try and make a FQDN that resolves to something.

 

Can you compare the "DNS suffix search order" of a machine that works against a problem machine? "ipconfig /all" will show you.

Edited November 8, 2013 by jinnantonnixx

[klop]

Ok, massive embarrassment time!!

 

In the first post of this thread you may have noticed I had mentioned we are switching to wpad.dat for our proxy settings.

We have been using up till now proxy.pac files.

 

The laptops that couldn't see the server by hostname in ie is now fixed, erm - there needed to be the exception for that within the wpad file... ooops!

 

Where I got confused was;

 

a> the netbook and the desktop that managed to connect to the server using hostname in ie and could get online

b> the laptop that did connect to server hostname in ie - but turns out isn't for another reason (possibly dns related?!?!?) picking up the wpad.dat file so isn't actually getting online!

 

The netbook and desktop have fixed proxy settings given by gpo. We're not intending they'll ever be use outside of school.

The laptop that wont connect online - well that's another story - and perhaps, another thread!

 

Thanks again for everyone's help and support - sorry I've wasted your time.

 

Cheers.