R7000 DHCP offer but no connection can be made on 5Ghz band

[ringlord]

R7000 Windows10 / Android 

Firmware = 1.0.7.2

Modem = 192.168.0.1

Router = 192.168.1.1  (R7000)

Hi I had a horrible weekend getting my R7000 to work again after replacing the modem from the ISP.

Problems started when my new Modem was acting as a DHCP server during initial setup.

When I switched that off, my R7000 would not serve IP addresses to machines that previously received an IP from the modem.

I got these errors on the clients : “An error occurred while renewing interface Local Area Connection : The name specified in the network control block (NCB) is in use on a remote adapter.”

Unfortunately, there is no way to reconcile the DHCP database on the R7000.

So I ended up loading the latest firmware again and factory resetting 2x.

In the end I got most of it to work again, except the 5Ghz band.

When a client tries to connect to 5Ghz, I see a 'DHCP IP' in the log of the R7000 every 10 seconds but the client will not connect.

Clients that I tried were Nexus 5 and Nexus 7.

Tried changing the channel on the R7000 (44 / 48 / 100) the setting is for Europe.

There is no problem connecting to the 2.4 Ghz band.

What can I do besides factory resetting again and again?

[ElaineM · Accepted solution]

Welcome to the community, @ringlord

Sounds like a faulty router. 

Can you try the following reset below then reconfigure the router.

1. With the unit powered on, press and hold the reset button on the back of unit for 30seconds.

2. Without releasing the reset button, unplug the unit and hold reset for another 30 seconds.

3. Power on the unit while STILL pushing the reset button and count for another 30 seconds before letting it go. 

Try to reconnect your devices on 5GHz and see if it will work.

[ringlord]

PS This is what we can see in the log :

[DHCP IP: (192.168.1.2)] to MAC address CC:FA:00:B4:EE:48, Monday, Nov 28,2016 19:41:12
[DHCP IP: (192.168.1.2)] to MAC address CC:FA:00:B4:EE:48, Monday, Nov 28,2016 19:41:02
[DHCP IP: (192.168.1.2)] to MAC address CC:FA:00:B4:EE:48, Monday, Nov 28,2016 19:40:52
[DHCP IP: (192.168.1.2)] to MAC address CC:FA:00:B4:EE:48, Monday, Nov 28,2016 19:40:42

[ElaineM · Accepted solution]

Welcome to the community, @ringlord

Sounds like a faulty router. 

Can you try the following reset below then reconfigure the router.

1. With the unit powered on, press and hold the reset button on the back of unit for 30seconds.

2. Without releasing the reset button, unplug the unit and hold reset for another 30 seconds.

3. Power on the unit while STILL pushing the reset button and count for another 30 seconds before letting it go. 

Try to reconnect your devices on 5GHz and see if it will work.

[ringlord]

Thanks @ElaineM it has been a rough ride with this router.

Your reset procedure seems to have helped quite a bit since I now can connect on the 5Ghz band but I am not yet completely convinced that the connection is stable since I sometimes still get network connection errors for example on my Nexus 5.

Also the speed of 50/6 on the 5Ghz channel is less then I used to get.

I append the new logfile here so you can see that still multiple DHCP offers were needed but eventually the connection succeeded.

The odd thing about this reset procedure is that my settings were retained. (I tried it twice with the same result)

[DHCP IP: (192.168.1.10)] to MAC address CC:FA:00:B4:EE:48, Wednesday, Nov 30,2016 21:59:56
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:59:17
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:59:07
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:58:57
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:58:47
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:58:37
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:58:21
[DHCP IP: (192.168.1.8)] to MAC address B8:E9:37:EE:77:72, Wednesday, Nov 30,2016 21:58:21
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:58:18
[DHCP IP: (192.168.1.8)] to MAC address B8:E9:37:EE:77:72, Wednesday, Nov 30,2016 21:58:18
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:58:16
[DHCP IP: (192.168.1.9)] to MAC address B8:E9:37:EE:76:FC, Wednesday, Nov 30,2016 21:58:16
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:58:15
[DHCP IP: (192.168.1.8)] to MAC address B8:E9:37:EE:77:72, Wednesday, Nov 30,2016 21:58:15
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:58:13
[DHCP IP: (192.168.1.9)] to MAC address B8:E9:37:EE:76:FC, Wednesday, Nov 30,2016 21:58:13
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:58:12
[DHCP IP: (192.168.1.8)] to MAC address B8:E9:37:EE:77:72, Wednesday, Nov 30,2016 21:58:12
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:58:07
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:57:57
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:57:47
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:57:37
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:57:27
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:57:17
[Time synchronized with NTP server] Wednesday, Nov 30,2016 21:57:16
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:57:14
[DHCP IP: (192.168.1.7)] to MAC address A4:77:33:3E:7C:C0, Wednesday, Nov 30,2016 21:57:13
[DHCP IP: (192.168.1.6)] to MAC address 1C:6F:65:C8:C5:F4, Wednesday, Nov 30,2016 21:57:13
[DHCP IP: (192.168.1.5)] to MAC address 20:78:F0:31:08:F8, Wednesday, Nov 30,2016 21:57:13
[DHCP IP: (192.168.1.3)] to MAC address 24:DA:9B:01:55:2E, Wednesday, Nov 30,2016 21:57:12
[Internet connected] IP address: 91.177.37.230, Wednesday, Nov 30,2016 21:57:11
[DHCP IP: (192.168.1.2)] to MAC address D8:50:E6:90:92:4E, Wednesday, Nov 30,2016 21:57:08
[DHCP IP: (192.168.1.4)] to MAC address 8C:C1:21:5B:60:75, Wednesday, Nov 30,2016 21:57:04
[Initialized, firmware version: V1.0.7.2] Wednesday, Nov 30,2016 21:57:02

[ElaineM]

If it keeps disconnecting, try to check for other channels. 

You may also want to try to adjust the Fragmentation Length and CTS/RTS Threshold to 2304. 

Then reconnect to the network.