• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1511
  • Last Modified:

Windows SBS2008, DNS issues, can't connect to internet or resolve IP addresses.

I am changing the configuration on an SBS2008 server, long story short, there were 2 x internet connections running on the same LAN. One gateway was 192.168.2.254 (no longer active), the other is 192.168.2.253 (Telstra cable, still active). All was working O.K until we disconnected the .254 gateway. At this time I changed the gateway on the LAN adapter on the server to 192.168.2.253, left the current static IP as it was 192.168.2.20, and left the DNS entry on the LAN adapter as it was 192.168.2.20 (the server is running DNS so should use itself as the primary DNS).

 I added 2 x forwarders to the DNS properties (DNS servers from the ISP). But the DNS server is unable to resolve them.

 I can get to the gateway through IE (192.168.2.253), but can't ping any IP or address outside the LAN.

 The server won't connect to the internet, but other PC's on the network can access the server (file sharing).

 What am I missing? I can supply screen shots if there is anything particular you want to see to help in the diagnosis.

 Your help appreciated in advance.
0
Killersmits
Asked:
Killersmits
  • 12
  • 6
  • 3
  • +1
3 Solutions
 
David Johnson, CD, MVPOwnerCommented:
try setting the ip address as dynamic as a test and see what results you get from ipconfig and see if you have internet access or if the forwarders resolve.. does your server have the dhcp role?
0
 
KillersmitsAuthor Commented:
Yes it does have the DHCP role and it hands out address fine to the workstations. I don't want to set the server to DHCP even temporarily, it's in use most of the time. But the gateway is 192.168.2.253 (which is the gateway and I can reach it via IE) and the DNS is 192.168.2.20 (same as the server IP).
0
 
Cris HannaCommented:
Have you tried re-running the connect to the internet wizard?
0
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 
Mark GalvinManaging Director / Principal ConsultantCommented:
If you run a tracert to an external address, say 8.8.8.8 (Google DNS) where does it drop?
0
 
KillersmitsAuthor Commented:
Ran the tracert as requested here are the results
tracerts-results.jpg
0
 
Mark GalvinManaging Director / Principal ConsultantCommented:
Right. All the hops from 3 onwards seem to be external IPs, which would indicate some internet connectivity.

Do you know what those IPs are?

Thanks
Mark
0
 
Cris HannaCommented:
Very unusual to have 2 "gateway" connections plugged into the LAN...typically you do this with one LAN connection and two WAN connection.    So how did you configure traffic as to which gateway to use?   Do you have more than one nic live on the server?   If so, remove or disable it.

Again I would suggest that you re-run the connect to the internet wizard, this is where you'll get the biggest bang in terms of "re-training" the network on which connection to use.  

Have you checked DHCP scope and server options to insure the old gateway is not hard coded there?

I would also run the Fix My Network Wizard on the SBS console.
0
 
KillersmitsAuthor Commented:
Mark - No. All IP's from 192.168.2.253 onwards are external and not relevant I don't believe.

Cris - Yes it is unusual. I didn't set it up that way I have just been left to clean up the mess. The reason there were 2 x gateways originally was that the SBS server was hosting email and ideally needed an internet connection with a static IP. But that connection wasn't very fast so they had one slow ADSL connection that was static (.254) and one fast connection that was dynamic (.253). We have moved the email off to a cloud service, and are now just trying to simplify the system. So we are removing the now useless internet connection (.254) and leaving just the  (.253)

Only a single NIC, I believe the server just had .254 as the gateway on the NIC which I have now changed to .253.

But for some reason the server won't browse through .253, and not resolve IP addresses through DNS.

Yes I have checked the DHCP scope and there is no mention of .254 there.

I will see if we can get users off the server to try the Fix My Network wizard, although I think I have tried that with no improvement.
0
 
Cris HannaCommented:
But have you re-run the "Connect to the Internet" wizard?   Is the IPv6 protocol enabled?
0
 
KillersmitsAuthor Commented:
I have re run the connect to internet wizard, and attached are the screen shots for the 2 steps it goes through.

I have disabled IPv6 to rule out that being the problem.
Connect-to-internet-wizard-step-1.JPG
connect-to-internet-step-2.JPG
0
 
Cris HannaCommented:
IPv6 must be running
I would download and install and run the SBS2008 BPA and fix everything it finds
0
 
KillersmitsAuthor Commented:
I have run the SBS2008 BPA tool and the results are attached. I don't think this helps unfortunately. I have re-enabled IPv6. Mysteriously the server now thinks it has internet connectivity. The icon the in the bottom right corner says internet , where as in the past it has complained that it doesn't have internet access. However I still can't connect to the internet, nor does the server resolve DNS requests for itself or other users.

See the screen shots attached for more info.
SBS2008-BPA-results.JPG
PF-system-tray.JPG
DNS-forwarders.JPG
0
 
David Johnson, CD, MVPOwnerCommented:
do you have the correct gateway set up in your network configuration?
0
 
KillersmitsAuthor Commented:
Yes I do have the correct Gateway. 192.168.2.253, which as previously mentioned I can connect to via IE from the server.

See screen shot.
PF-NIC-and-gateway.JPG
0
 
David Johnson, CD, MVPOwnerCommented:
is the dhcp function on the router disabled and dhcp enabled on the correct interface on the SBS box.. also in dns uncheck the unused interface and check via the monitoring tab in dns manager that you can do a recursive and simple query
0
 
Cris HannaCommented:
Can the server ping it's self by name and by IP address?
0
 
KillersmitsAuthor Commented:
David, yes the DHCP function is disabled on the router, but found an interesting fact, there are 2 authorized DHCP servers in the scope, 1 is 192.168.2.20 (the SBS server) the other is 192.168.2.2 (no idea what this is, probably an old router). The simple DNS test passes, the recursive fails.


Cris - The server can ping itself by IP and name, the screen shot shows the name by IPv6, but I checked and it will do it via IPv4 as well.

Take  a look at the screen shots and see if anything jumps out at you. Much appreciate this help guys it's a great help as Im outta ideas.
PF-dns-and-dhcp.JPG
0
 
Cris HannaCommented:
You definitely remove the bad DHCP Server...SBS gets upset if it thinks there is another DHCP Server
0
 
KillersmitsAuthor Commented:
I removed the 2nd DHCP server, no difference from what I can see.

The other thing I noticed and have changed to test is there was a specified IP and DNS address in the IPv6 properties for the local NIC. I told it to get address automatically rather than have a designated address. Again no change, but I thought it was worth a shot as perhaps the server was trying to browse via IPv6 rather than IPv4?? I don't know anything about IPv6 so thought it was worth a shot.

See the attached screen shot for the settings that were in the IPv6 properties. I have changed to obtain automatically now. Good idea, bad idea?
PF-ipv6.JPG
0
 
KillersmitsAuthor Commented:
Bump - Im still wanting any more suggestions on this issues fellow Experts. I haven't made any further progress on this since the last post. My next idea is to go and install a router to manage the DHCP and DNS for the network, and turn the current Telstra modem into bridge mode. Im hoping that will then allow at least all the clients to get IP addresses, and hopefully get the server to browse as well.

Suggestions?
0
 
KillersmitsAuthor Commented:
Update - So I went to the site on the weekend. Had a few ideas up my sleeve but thought I'd go for the simplest first. I changed the IP address of the server to 192.168.2.5 (from 192.168.2.20). Rebooted and what do you know, it worked!

Everything came good. Can browse, can use server as DNS/DHCP.

I can only assume an IP conflict with some other device hiding on the network. There are lots of random wireless access points, Power over Ethernet adapters, printers, amplifiers and media players connected. None of which were setup by me originally so who know which is the issue.

Anyway working now, as is usually the case a simple fix, not some horribly complicated issue that I lie awake at night worrying about.

Cheers for your help guys.
0
 
KillersmitsAuthor Commented:
I've requested that this question be closed as follows:

Accepted answer: 0 points for Killersmits's comment #a40348909

for the following reason:

Thanks to Cris and David for your help.
0
 
KillersmitsAuthor Commented:
Wanted to give you guys as many points as possible for your help. Thanks again.
0

Featured Post

Restore individual SQL databases with ease

Veeam Explorer for Microsoft SQL Server delivers an easy-to-use, wizard-driven interface for restoring your databases from a backup. No expert SQL background required. Web interface provides a complete view of all available SQL databases to simplify the recovery of lost database

  • 12
  • 6
  • 3
  • +1
Tackle projects and never again get stuck behind a technical roadblock.
Join Now