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Posted

I’ve been having some odd DNS issues, I’m hoping for suggestions on where to look to solve these problems.

 

VBs login scripts aren’t always triggering, unless the user has a static IP.

 

New machines cann't join our domain, (though I do get a prompt for a user/password)

dns_error1.png

 

From new machines (with ips designated by our DHCP) I can’t ping our FQDN of parkcounty.int, however the ipconfig on the machine that can not connect is as follows

 

Ethernet adapter Local Area Connection:

 

Connection-specific DNS Suffix . : parkcounty.int

Link-local IPv6 Address . . . . . : fe80::b460:5249:17d7:d177%11

IPv4 Address. . . . . . . . . . . : 10.1.2.133

Subnet Mask . . . . . . . . . . . : 255.255.0.0

Default Gateway . . . . . . . . . : 10.1.1.254

 

Unfortunately, these DNS issues are also stopping our Web filtering appliance to work correctly and even some staff have to input their username/password to connect with Exchange several times an hour.

 

Thanks in advance for any suggestions.

Posted
Also, when I run the Best Practices for our DNS the only error I get is that I do not have the 127.0.0.1 as my secondary dns set on the NIC.
Posted
Are the dns servers listed in your ipconfig output?

 

Ben

 

From the new machine that wont connect, here is the full Ipconfig:

 

 

Windows IP Configuration

  Host Name . . . . . . . . . . . . : dmeads1
  Primary Dns Suffix  . . . . . . . : 
  Node Type . . . . . . . . . . . . : Hybrid
  IP Routing Enabled. . . . . . . . : No
  WINS Proxy Enabled. . . . . . . . : No
  DNS Suffix Search List. . . . . . : parkcounty.int

Wireless LAN adapter Wireless Network Connection:

  Media State . . . . . . . . . . . : Media disconnected
  Connection-specific DNS Suffix  . : 
  Description . . . . . . . . . . . : 1x1 11b/g/n Wireless LAN PCI Express Half Mini Card Adapter
  Physical Address. . . . . . . . . : D0-DF-9A-46-50-C4
  DHCP Enabled. . . . . . . . . . . : Yes
  Autoconfiguration Enabled . . . . : Yes

Ethernet adapter Local Area Connection:

  Connection-specific DNS Suffix  . : parkcounty.int
  Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
  Physical Address. . . . . . . . . : E8-9A-8F-8D-80-C6
  DHCP Enabled. . . . . . . . . . . : Yes
  Autoconfiguration Enabled . . . . : Yes
  Link-local IPv6 Address . . . . . : fe80::b460:5249:17d7:d177%11(Preferred) 
  IPv4 Address. . . . . . . . . . . : 10.1.2.133(Preferred) 
  Subnet Mask . . . . . . . . . . . : 255.255.0.0
  Lease Obtained. . . . . . . . . . : Tuesday, August 30, 2011 6:45:10 AM
  Lease Expires . . . . . . . . . . : Wednesday, August 31, 2011 12:45:53 PM
  Default Gateway . . . . . . . . . : 10.1.1.254
  DHCP Server . . . . . . . . . . . : 10.1.1.254
  DHCPv6 IAID . . . . . . . . . . . : 250124943
  DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-15-BE-D6-D7-E8-9A-8F-8D-80-C6
  DNS Servers . . . . . . . . . . . : 64.25.238.120
                                      64.25.227.34
                                      8.8.8.8
  NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.{236FC1F9-C64F-44D0-BA89-BD512AACAC7E}:

  Media State . . . . . . . . . . . : Media disconnected
  Connection-specific DNS Suffix  . : 
  Description . . . . . . . . . . . : Microsoft ISATAP Adapter
  Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
  DHCP Enabled. . . . . . . . . . . : No
  Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 11:

  Media State . . . . . . . . . . . : Media disconnected
  Connection-specific DNS Suffix  . : 
  Description . . . . . . . . . . . : Microsoft 6to4 Adapter
  Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
  DHCP Enabled. . . . . . . . . . . : No
  Autoconfiguration Enabled . . . . : Yes

Tunnel adapter isatap.parkcounty.int:

  Media State . . . . . . . . . . . : Media disconnected
  Connection-specific DNS Suffix  . : parkcounty.int
  Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
  Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
  DHCP Enabled. . . . . . . . . . . : No
  Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

  Connection-specific DNS Suffix  . : 
  Description . . . . . . . . . . . : Microsoft Teredo Tunneling Adapter
  Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
  DHCP Enabled. . . . . . . . . . . : No
  Autoconfiguration Enabled . . . . : Yes
  IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:82d:f0a:f5fe:fd7a(Preferred) 
  Link-local IPv6 Address . . . . . : fe80::82d:f0a:f5fe:fd7a%28(Preferred) 
  Default Gateway . . . . . . . . . : ::
  NetBIOS over Tcpip. . . . . . . . : Disabled

Posted

DNS Servers . . . . . . . . . . . : 64.25.238.120

64.25.227.34

8.8.8.8

 

Is this what you're using on your ones with static IPs?

 

Do those DNS servers know about parkcounty.int? (they look like public DNS servers)

Posted
Is this what you're using on your ones with static IPs?

 

Do those DNS servers know about parkcounty.int? (they look like public DNS servers)

 

First, thank you all for your quick replys.

 

actually, these DNS IPs aren't anywhere on my DNS server (not even o nthe NIC configs).. They are however on my gateway. I just remoted into the gateway and disabled the VPN settings on it in case that was somehow causeing the fits. Not sure how quickly I'll see changes in my network though.

Posted

It looks to me you have no internal DNS - generally not a good idea, especially as you're running a network domain.

 

Typically your primary DNS is the same as your DHCP server, so in your case it would look like:

 

10.1.1.254
64.25.238.120
64.25.227.34
8.8.8.8

Posted

By the looks of it as has been said you are not giving out your domain controller / dns servers to your clients therefore active directory is not going to be working correctly.

 

Ben

Posted

Agreed. Internal DNS doesn't show. From the domain controller (Windows 2008 with AD, DNS, DHCP) client machines aren't seeing the internal DNS, and I haven't a clue why. It has been working fine for a few years, then, it has stopped.

While at the DNS snapin, everything is running. .. Going to restart the entire network and hope that solves something.

Posted
It looks to me you have no internal DNS - generally not a good idea, especially as you're running a network domain.

 

Typically your primary DNS is the same as your DHCP server, so in your case it would look like:

 

10.1.1.254
64.25.238.120
64.25.227.34
8.8.8.8

 

My internal DNS server has one DNS as itself, 10.1.1.2. The Second DNS (set on the nic) is 127.0.0.1.

As far as I know, I have no ither DNS server listed on my DNS server. If you have an idea where to look to double check this, I'll look, but I don't know why or where they would be.

Posted

Is DNS being set using server option on your dhcp server?

 

Your clients should only have you AD/DNS server ip's as their DNS and no others.

 

Ben

Posted
Is DNS being set using server option on your dhcp server?

Ben

Yes, Name Servers, DNS Servers and DNS Domain Name.

Your clients should only have you AD/DNS server ip's as their DNS and no others.

Ben

Agreed. This has only recently changed. I think some clients are grabbing that info from our gateway. Not sure why they aren't getting it from the DNS server.

Posted (edited)

I have had it where some of my clients get strange DNS addresses. I figured out that it was due to a rogue device dishing out DHCP requests on my VLAN. The only thing that I can figure was happening was that the correct DHCP server was responding in time for the IP to be assigned and then some how the other server's response dished out the DNS.

 

Check that DHCP isn't enabled on any other device on your network. First place I would look would be your gateway as its where you have seen the IP for those DNS servers before.

 

Things like Internet Connection Sharing on a client will set up a crude DHCP server on that client.

 

Alternately depending on your standard lease time from your DHCP you could temporarily stop the DHCP service. Then run ipconfig /release & ipconfig /renew on a client and see if it still gets a response (if it does then the IP of the DHCP Server will be your culprit)

Edited by iMash
Posted
My internal DNS server has one DNS as itself, 10.1.1.2. The Second DNS (set on the nic) is 127.0.0.1.

As far as I know, I have no ither DNS server listed on my DNS server. If you have an idea where to look to double check this, I'll look, but I don't know why or where they would be.

 

Normally any Active Directory domain uses DNS integrated (by default), so this would apply to 2000/2003 and 2008 Server. If you navigate to Start > Administrative Tools > DHCP, expand the menu on the left until you see IPv4. Then expand 'Scope' and click 'Scope Options'.

 

There should be the following entries listed on the right:

 

003 Router

006 DNS Servers

015 DNS Domain Name

 

Double click to open '006 DNS Servers'. Now according to the information you've given, I want you to enter these addresses in this order:

 

10.1.1.254
10.1.1.2
64.25.238.120
64.25.227.34
8.8.8.8

 

Apply changes, then close DHCP Server.

 

Manually re-adjust your DNS settings on your server NIC to match the above. This basically means everything in your domain will talk to your on site server, before talking to the outside world.

 

Now restart a few of your workstations and hopefully they should logon correctly. Once logged in a workstation, open up a command prompt and enter:

 

ipconfig /all

 

Your IP configuration should look the same as specified above (for DNS servers). Hope this helps.

Posted
turns out my DHCP was currupted. Backing up the DHCP db, removing and reinstalling DHCP was the only answer, but it worked. Thank you all for the assistance!

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