jmair Posted August 30, 2011 Posted August 30, 2011 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) 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.
plexer Posted August 30, 2011 Posted August 30, 2011 Are the dns servers listed in your ipconfig output? Ben
jmair Posted August 30, 2011 Author Posted August 30, 2011 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.
jmair Posted August 30, 2011 Author Posted August 30, 2011 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
kmount Posted August 30, 2011 Posted August 30, 2011 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)
jmair Posted August 30, 2011 Author Posted August 30, 2011 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.
Michael Posted August 30, 2011 Posted August 30, 2011 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
plexer Posted August 30, 2011 Posted August 30, 2011 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
jmair Posted August 30, 2011 Author Posted August 30, 2011 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.
jmair Posted August 30, 2011 Author Posted August 30, 2011 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.
plexer Posted August 30, 2011 Posted August 30, 2011 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
jmair Posted August 30, 2011 Author Posted August 30, 2011 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.
iMash Posted August 31, 2011 Posted August 31, 2011 (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 August 31, 2011 by iMash
Michael Posted August 31, 2011 Posted August 31, 2011 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.
jmair Posted September 1, 2011 Author Posted September 1, 2011 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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