DNS and Forwarders

February 3, 2009 at 08:53:00
Specs: Server 08, Quad Core
Hello,

I have a server 08 box that can't see the internet for some reason or forward the correct dns IPs to the workstations. I have the correct dns forwarders setup in DHCP, but still no internet. If I set a workstation on the network, connected to the same switch, to a static DNS of the ISP primary/secondary the workstation will get right on. I tried the same thing on the server but still no internet. Router is wide open so nothing is being blocked.

Other then the ISP DNS IPs the workstations are working great and all information is assigned correctly from the server.

I can't ping google.com from the server, by IP or Name.

Me


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#1
February 3, 2009 at 10:38:09
Check, whether the standard gateway at the server is set up correctly.
If there are 2 NICs installed, only the interface, that connects to the Internet should have an entry for the standard gateway.
If there is a router between the server and the internet, gateway address is the routers address, e.g. 192.168.0.1.
If the server is directly connected to the modem, the servers internet nic should be set to DHCP, to get all informations automatically from the ISP.

Please send a reply, if you solved the problem !!!


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#2
February 5, 2009 at 06:48:39
-One NIC
-Gateway setup correctly to router, also should mention router status is reporting correctly and modem is in bridge mode. Again, the other computers can connect to the internet if I statically set the DNS to the ISPs IP Primary\Secondary DNS.

I'm looking into this most of the day today so if I find anything will post back. Suggestions still appreciated!

Me


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#3
February 5, 2009 at 08:43:14
Let's summarize.
1. Modem in bridge mode
2. Router does the authentication at the ISP, gets the public IP and one or 2 DNS servers from the ISP
3. Server is connected to the Router, runs DHCP and DNS. Forwarders in the servers DNS configuration should be the Routers IP. So if the server can't resolve the names, it asks the router and the router asks the ISPs DNS servers.
4. Workstations standard gateway is the servers IP, DNS is also the servers IP.
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OK, starting at the server.
First of all, the server must be able to resolve domain names. So e.g. a tracert google.com should show the hops with IP and names.
If this doesn't work, does the router can act as a DNS server?

Please send a reply, if you solved the problem !!!


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Related Solutions

#4
February 5, 2009 at 08:47:39
The forwarders must be configured in DNS management console not in DHCP management console.
If you configure DNS server in DHCP, the workstations will get this as the workstations DNS server.

Please send a reply, if you solved the problem !!!


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#5
February 5, 2009 at 12:57:26
Hello, still working on this.

Server is doing DHCP and DNS.
-DHCP is setup with scope options of Router IP, DNS server IP of the 08 server.
-DNS is setup to listen on all IP address for DNS queries and forwarders setup to the ISPs Primary\Secondary DNS.

I can ping the Primary\Secondary DNS IPs from the router, I can ping them also from the workstations that have their TCP\IP DNS settings statically set. Nothing will get through on the server though.

I've checked to see if the router might be blocking something. I've let everything through the firewall in the router and the server. I've tried turning the firewall off. No third party applications are installed either.

I can't ping anything external from the server. The router might be able to handle DHCP and DNS but I don't want it to in a domain environment.

Any other ideas?

Me


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#6
February 5, 2009 at 18:59:50
What does a tracert 209.85.171.100 (this is google.com) should show, that the server tries to use the router and then the ISPs gateway a.s.o.

Does this work for you?
If not, it's a routing problem.

If so, try a tracert google.com. If this will not work, the name resolution is the problem.

If possible, post both results.

Please send a reply, if you solved the problem !!!


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#7
February 6, 2009 at 10:56:24
Tracert dies on both, doesn't resolve.

The only thing I can think of is the ISP doesn't have recursive DNS. Therefore, DNS forwarders won't resolve within the server's DNS setup.

I'm still looking

Me


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#8
February 6, 2009 at 12:23:17
If you to a tracert to an ip address, there is no dns needed.
So your problem is the routing.
The tracert should show at minimum the router as the first hop.

Can you ping the routers private ip?
If so, can you ping the ISPs gateway, means the default gateway of the router. You can figure out this address in the router setup status page, I guess.

Please send a reply, if you solved the problem !!!


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#9
February 20, 2009 at 12:08:57
Fixed the issue.

cmd prompt
Route delete 0.0.0.0
Restarted the server...wow frustrating.

DNS wouldn't resolve due to the persistent gateway of the 0.0.0.0, by manually deleting this dns finally resolved since the gateway was correct. Problem is the server was set to a static IP so the 0.0.0.0 never would've showed with a ipconfig.

Me


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