No dns sever?

[stubuzz]

The place where i live gets frequent power cuts. I have a router/access point in my room that is connected to the buildings main server and after the power goes off i sometimes cannot connect to the net though Ethernet because it is not getting auto dns sever allocation. It will say connected to the net but opening the browser shows a no dns error. However, i can connect and use the net on a WiFi connection. If i manually add the ipv4 address to the Ethernet connection in settings, it will work again.

 

Is the router faulty or could it be an ip address conflict? Any ideas?

 

 

 

[degrub]

Maybe there are multiple things going on. I’m assuming you are using MS Windows.

 

If, by manually entering a tcp/ip address for your device and changing “get address automatically “ to “ manual” , you restore access to the internet, that means that a router with a DHCP server is not active on your LAN AND the ip address lease on your device is uncommonly short duration. Your device should not be loosing its IP address just because of a power failure on the network. It retains its address until its address lease expires or it is rebooted.

 

If you are entering a tcp/ip address in the field “preferred dns server” or “alternate dns server”, then that indicates that the dns server you would normally access, either automatically or manually, is not reachable. 
 

So , figuring out where that failure is occurring depends on if the device in your room is a router or an access point.  Is the device provided by the building management or by you ?

Does building management provide the access to the internet or do you ?

 

If you go to windows start menu and enter cmd in the search box, select the cmd program entry and type 

ipconfig /all

it will return the details of all of your network configuration including your current ip address and lease expiration, DHCP server ip address,  DNS server addresses, and default gateway.

 

you can do this when everything is working and when it stops working to see what, if anything, has changed. You can run the PING command to determine if the ip address for the DHCP server, the DNS server, and the Gateway are reachable from your device.

 

ping 192.168.1.1 for example.

 

 

 

 

 

[stubuzz]

1 hour ago, degrub said:

 Is the device provided by the building management or by you ?

Does building management provide the access to the internet or do you ?

The device is provided by the building management. I think it is configured as an access point.

 

1 hour ago, degrub said:

DHCP server ip address,  DNS server addresses, and default gateway.

When working, the addresses for ethernet and wifi are the same, but not net connection when opening a browser on ethernet. If you manually change the dns address and save it the ethernet works for about 15 seconds. Note: the wifi connection works all of the while.

 

It seems that the only way to fix this is to to a hard reset on the main server and router. Then 9/10 times the problem will resolve itself.