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Hello,

Hopefully someone here can answer this question for me. I recently did a server migration for a small business. The have a Ubiquity Access Point that was working fine prior to the migration. Once the migration was done, we noticed the AP was offline. We reset and reconfigured it to received the appropriate IP settings. Users are able to connect to it just fine, however when it comes time to go out to the interntet, we keep getting a message about DNS cannot be found.

I can ping the gateway, other machines on the network, and even 8.8.8.8 (Google's DNS), but not a website. So I know the issue is DNS related. On the new server, everything looks fine with the DNS settings. I'm wondering if I need to remove the current DNS zone and create one.

Any assistance from anyone would be greatly appreciated.

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Last Post by jacks009
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So you checked AP, server, some IPs but I can't see where the client IP settings were checked. Many new networkers won't share LAN addresses as they are just new and fearful. No one can hack your 192.168.x.x address.

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Thanks for your reply. I'm not on site now, but I can remote into their server. Below are the IP settings for the server. They're on a 192.168.0.X subnet:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Broadcom NetXtreme Gigabit Ethernet #2
Physical Address. . . . . . . . . : 14-18-77-33-33-AF
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 192.168.0.3(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.0.1
DNS Servers . . . . . . . . . . . : 127.0.0.1
NetBIOS over Tcpip. . . . . . . . : Enabled

The AP is set to DHCP, and is assigned 192.168.0.13 when I was there last. I'm not able to log into the configuration of the AP unless I'm on site. Everything seems to be connected just fine, but DNS is just not doing what it's supposed to be doing on the server. Also, the server has the role of DHCP. Its turned off on the Firewall/router. Not sure if that could be part of the problem. Like I said, I can ping 8.8.8.8 when I'm connected via wireless, but not to Google's website or any other website, which means its a DNS issue.

These are all the devices connected to the network:
Interface: 192.168.0.3 --- 0xd

  Internet Address      Physical Address      Type

192.168.0.1 00-1b-2f-2f-a3-d7 dynamic
192.168.0.12 04-18-d6-20-55-1b dynamic
192.168.0.13 08-bd-43-b5-f8-d0 dynamic
192.168.0.18 90-4c-e5-71-7a-91 dynamic
192.168.0.19 50-65-f3-4c-09-a6 dynamic
192.168.0.23 50-65-f3-39-2b-81 dynamic
192.168.0.28 50-65-f3-4c-0a-0e dynamic
192.168.0.30 50-65-f3-4b-0d-f1 dynamic
192.168.0.100 50-65-f3-4c-0a-6d dynamic
192.168.0.110 0c-54-a5-05-d8-77 dynamic
192.168.0.124 08-00-37-ea-b4-f7 dynamic
192.168.0.255 ff-ff-ff-ff-ff-ff static
224.0.0.2 01-00-5e-00-00-02 static
224.0.0.22 01-00-5e-00-00-16 static
224.0.0.252 01-00-5e-00-00-fc static
224.0.0.253 01-00-5e-00-00-fd static
224.0.1.55 01-00-5e-00-01-37 static
233.89.188.1 01-00-5e-59-bc-01 static
239.255.255.250 01-00-5e-7f-ff-fa static
239.255.255.254 01-00-5e-7f-ff-fe static
255.255.255.255 ff-ff-ff-ff-ff-ff static

Hope that's enough information. Let me know if more information is needed. Thanks in advance for your help!

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The line that jumps out at me is:

DNS Servers . . . . . . . . . . . : 127.0.0.1

That would, on a client tell us the DNS (server) is us. That's rare.

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Yeah, that's the ip settings on the server, which is the Domain Controller.

That setting is usually normal in a domain controller environment. I can give it the specific ip of 192.168.0.3, which is its own ip address since its also the DNS. Would that make a difference?

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I asked for the client IP settings. 127.0.0.1 would be a failure point. You are close to solving this as it is indeed a DNS issue. But here I only have what you share and maybe you posted it but I don't see it. What are the client IP settings?

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I thought I posted that in the previous post I copied. The IP settings from the client's server is:
192.168.0.3
255.255.255.0
192.168.0.1
DNS: 127.0.0.1 (if this is a failure point, maybe chaning to 192.168.0.3 might help, let me know if this is what you would suggest)

The AP's IP settings (Set to DHCP) are:
192.168.0.13
255.255.255.0
192.168.0.1
DNS: 192.168.0.3

The network is on a 192.168.0.x subnet. So all the other machines connected are all on the same subnet, including the AP. Hope that helps.
Thanks again for the help!

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Are you asking for their external IP settings given by their ISP?

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Not yet. I can't find how the client resolves addresses yet. The client's DNS entry is eluding me here. I'm not saying you didn't share it but I can't find it above so far.

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Here are the ip settings for one of the client:

Description . . . . . . . . . . . : Realtek PCIe FE Family Controller
Physical Address. . . . . . . . . : 0C-54-A5-05-D8-77
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 192.168.0.110(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Friday, April 22, 2016 1:15:14 PM
Lease Expires . . . . . . . . . . : Wednesday, May 04, 2016 5:14:26 PM
Default Gateway . . . . . . . . . : 192.168.0.1
DHCP Server . . . . . . . . . . . : 192.168.0.3
DNS Servers . . . . . . . . . . . : 192.168.0.3
NetBIOS over Tcpip. . . . . . . . : Enabled

This client is set to DHCP.

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192.168.0.3 is the DNS server? That's odd in a few ways. I'm missing the big picture here but I had thought the the .1 machine had the DNS duties. What is 3?

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The machine with the ip 192.168.0.3 is the DNS server. Its also the local server/domain controller. 192.168.0.1 is the gateway, which is a netgear firewall. So every machine that has joined this domain is assigned an ip that's on the subnet of 192.168.0.x.

The first set of ip addresses that I showed you was from the server/domain controller. Its ip address is 192.168.0.3. And because its also the DNS server, that's why its DNS is 127.0.0.1. Every other machine on the network is assigned 192.168.0.3 for the DNS.

Does that explain things better?

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OK, now run NSLOOKUP on the client that doesn't work and see if NSLOOKUP works.

This is starting to sound as if the Ubiquity is the issue. I'm not using their product so you may have to call them if this is the cause of the issue. We've done the rest of the checking so what remains is the Ubiquity.

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From server at 192.168.0.3. It is the DNS for the network. Thus it should also have Forwarders setup in it's DNS config so that anything it can't resolve gets sent out to another 3rd party dns server (i.e. 8.8.8.8 or 4.2.2.1).

From the client, if you can ping something internally, but dns fails when going to an external site, then the Forwarders are probably incorrect.

On a client or even on the server, check dns by opening a command prompt:

NSLOOKUP
server 8.8.8.8
www.google.com
<here you should see a response showing google's ip>
server 192.168.0.3
www.google.com
<here, if you get a timeout, the server is not forwarding dns requests outbound or is blocked going out a tcp/udp 53>

Votes + Comments
Good NSLOOKUP example. Yes, use NSLOOKUP to test your DNS choices.
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Regarding the nslookup, I was working with Ubiquity support exclusively for a while, as I thought the issue was with them. They ran a couple of NSLOOKUP commands and saw that the AP was working fine with DNS. They concluded the issue is with the DNS server.

I will try that NSLOOKUP command from the server and see what I get. I'll let you know the results.

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It's going to be that.... I'll bet.

DNS server is either not forwarding, or is forwarding to old dns servers.

If you need to add dns forwarders.... 8.8.8.8 or 4.2.2.1/4.2.2.2 are reliable choices.

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I tried the forwarders and that didn't work. I put in all the public DNS that were recommended, 8.8.8.8, 4.2.2.1 and 4.2.2.2. I think the DNS component of the server might be corrupted. I was thinking of removing the DNS entirely and re-add it again on the server. This server was added to an existing forest, so I think some of the DNS properties from the old server is still playing a role somehow. The old server has been taken down.

If I deleted the current DNS settings and configured a new one, would that make a difference? Somehow I think it will. However, Im not sure what the consequences of deleting the current settings will be.

Also, I noticed when I connected my laptop to the Wi-Fi and statically assigned the DNS server (192.168.0.3), it was then able to go out the internet. The connection was kind of slow, but it still went out to the internet. That made me think that the DNS settings might be corrupted.

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Hey Guys,

I was able to solve this issue. It turned out that the DHCP service on the server had a bad scope. I removed the scope that was in there and also added an exclusion range, which was important to have. Once I added the new scope and activated it, I was then able to get access to the internet wirelessly.

Thank you all for your input.

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