All domain names are resolved into private addresses

[sxzhang23300]

Our wan network has several network segments. There is a problem with the DNS resolution of a network segment. The dns address is assigned by dhcp as 114.114.114.114. But the client cannot access the public network. Use nslookup baidu.com. It was found that the address was resolved to 192.168.1.1. However, there is no 192.168.1.1 address in the LAN. I don't know why this problem occurs. Attached is the result of nslookUp. There is also the result of capturing packets on windows.

Some clients have this problem, some do not.

WLC:3504

Version:8.10.130

AP:2802i

[marce1000]

 - Check the full client networking configuration when it gets on the wireless network , on windows for instance you can use ipconfig /all.     Make sure that everything makes sense : network  address , dns servers, default gateway.

 M.

[sxzhang23300]

I saw that the IP addresses obtained through dhcp are normal private IP addresses.

But once it is resolved, any domain name is pointed to 192.168.1.1. But some computers are normal

[sxzhang23300]

If I manually configure the IP address and dns address. Network is good.Anyone knows how to deal this problem?

[marce1000]

 - Check if the devices involved are really using DHCP by examining the DHCP servers logs and check if requests are being served from the corresponding MAC addresses

 M.

[sxzhang23300]

OK, because I tried to use wlc as dhcp. Or use firewall as dhcp. None of them work properly.

[marce1000]

       - Setup a dedicated dhcp server for the wlan and configure it correctly.

 M.

[craig.beck]

Is your DNS server filtering lookups or redirecting queries? Some DNS servers will send a response to a local block page, etc. if the URL is flagged as a specific category, or try to redirect to a setup page (example is home routers).

[sxzhang23300]

114.114.114.114 DNS server is the public dns server. We cannot modify the settings.And there are no '192.168.1.1' ip address in our private network.

[Scott Fella]

If you manually assign dns server to your device and everything works fine, then the issue point to the dns server that you are using.

[sxzhang23300]

I mean I manually set the IP address and dns address, which is good.

If the IP is automatically obtained and the dns address is manually set, it is still useless.

And the dns set manually and the dns address obtained automatically are the same.

This should not be a dns problem. Because under the same LAN, some clients are in normal use

I suspect it is a bug in the wireless version. But I did not find the corresponding evidence

[Scott Fella]

I really don't think so since wireless is just layer 2.  Setup dhcp on your switch or another device for testing and see if the issue stil happens.  I'm assuming that you are testing on multiple different machines?  If you connect a laptop to a wired port on the same vlan as the wireless, does it work?

[sxzhang23300]

after testing. The wired connection with vlan works normally.

[Scott Fella]

Okay so you must have something defined on the wireless NIC. Why don’t you remove the NIC from the device manager and have Windows install it back after a reboot. You must have something defined in the profile or something is wrong with your settings on that NIC.