Windows 2008 R2 - No internet access with static IP

Question

We had an internet outage and when the ISP resolved the problem, we ended up with a server that no longer has internet access unless we use DHCP.

I replaced the network card, thinking it might resolve the problem, but still no internet access. We have a domain, but I don't think that matters. I can see the machine on the network and remote to it, but the machine cannot access the internet. When I put the static IP in the network card and check verify and hit apply, then Windows finds a problem and wants to use DHCP. If I use DHCP then internet works, but we need the computer to use a specific IP because it is a web server. I don't think there is a conflict on the network, but is there anything else that can cause this problem?

Solution

(posting as an answer because comment is too large, but I'm a pretty good guesser :))

What exactly did your ISP do to "resolve" the problem?

EDUCATED GUESS TIME: If they replaced or had you reset the router (assuming small shop here) then it if I guess further, DHCP is controlled by that router and not your server, right? Would seem right based on your verbiage.

Sounds like you need to make sure that the LAN settings on the router are correct and on the same subnet as the static IP of the server. Making sure that the server's default gateway IP is the router's LAN IP and they are both the same subnet mask.

Also make sure that DNS is resolving correctly by pinging 8.8.8.8 first and checking for a response.

Comments

[EEAA]

Ensure your default gateway and DNS settings are correct.

[mfinni]

Also - unplug it and see if something is at the IP that it's supposed to be using.

[Tony]

yes, this is all correct. the setting are the same as we have used on this machine for years. Firewall is completely off.

[HopelessN00b]

Could also be a DNS issue. Can you ping external IP addresses, such as the Google DNS servers? (Use 8.8.8.8.)

[Paul Haldane]

Have you tried configuring the server statically with the DHCP address? That should show whether the problem is with the IP address or the configuration.

[Tony]

We have a juniper firewall, a managed switch and a domain controller. I wish it was something simple like wrong gateway, but that is all correct and verified. The juniper firewall controls the DHCP, static IP are below 100 and very tightly controlled. We only have about 8 server and a handful of other devices.

[krisFR]

@Tony You told me in comments that firewall is completely off, then you say you have a Juniper Firewall. Where is the truth ? is the Juniper Firewall off ? Maybe you could check its logs ?

[Tony]

Will try to rejoin to the Domain shortly. See if that tell use anything. We have reboot the entire network many times to try to resolve the issue. I don't think it is caching. We rebooted the Domain, Firewall, switch and client PC

[kralyk]

So what is the difference between a DHCP address and static one? DNS resolver differences? Did anything change on the Juniper firewall? Can you ping by IP?

[Tony]

The Windows Firewall is completely off. The Juniper is technically a firewall but acts as DHCP server.

[Tony]

should not be a firewall issue, since internet works when I let the DHCP server assign an address. I am started to suspect an IP conflict, but I do not have any idea how that would be possible in our environment. Or maybe the DNS server is confused by the new network card, but I doubt that is the problem, since the all NIC was behaving similar.

[mfinni]

Check the CAM tables on your switch. Check the DHCP server's lease database.

[Tony]

mfinni - good idea, I am trying to find them. Checked the lease tables but the IP addresses for DHCP are 100+ and the static IP is 17.

[kralyk]

I go back to "What exactly did your ISP do to resolve the problem?" - did you/they have to change ANYTHING on your end?

[Tony]

No, we didn't change anything. We didn't come back online so we rebooted our network. The one thing I changed is put a new NIC into this server that has a problem. I also have a VM that stuck in Access Only network mode and that is my next problem.

[HopelessN00b]

@Tony Gee, this is starting to a) feel more like an IP address conflict and b) like something you should bring in a networking engineer to figure out for you.

[murisonc]

IP address conflict sounds like a good path to go down. Also might want to try removing the network adapter in device management and then rescan to add it again.

[Tony]

Thanks all, this is pretty complicated. The Juniper has an interface with a couple of MIPS the seem to be no longer working. Not sure what is going on with it. Maybe is bad interface or maybe the public IP number on the interface is not working as it should