[Zelkovan]

So I've been trying to solve this silly issue and I can't figure out what's wrong. So, some background info:

I have a XB3 modem/router combo device (it's both in one) from Comcast. It was recently installed about a month ago in the house and I live at college so I haven't been in the house recently. For some reason, WiFi works fine on the device but Ethernet connections don't work at all. My desktop can only get to the internet through ethernet and when I troubleshoot for problems this pops up:

"Ethernet" doesn't have a valid IP configuration.

I've tried restarting the modem and computer, disabling/enabling or uninstalling and re-installing the drivers (unless i'm doing that wrong), resetting my IPV4 through cmd and manually entering the IP but none have worked so far. I know it's not the cord, because I've tried the cord on a different computer and it couldn't connect via ethernet and when I tried a different ethernet cord the same issue arose. When I tried it on the other computer it said that it was self-assigned an IP of 169.

Can anyone help me here? I'm pulling my hair out trying to fix this. Could it be an issue with the new modem or something from the ISP side?

 

[etaf]

lets see an ipconfig /all from a working wireless PC connected to the router - it is connected wireless to that router ??

and then a ipconfig /all from a pc connected to the ethernet only

------------------------------------------------------------------------

ipconfig /all

We would like to see the results from an ipconfig /all - post back the results in a reply here.

If you cannot access the internet with this PC, then you will need to paste the results into something like notepad and then copy onto a machine that can access the internet and post the results in a reply here.
Save the file to a USB flash drive or other removable media. Plug it into the working computer with internet access and copy the file and paste here.

If you do not have another PC - do you have a phone connected to the internet - can you photograph the result and post the image in a reply
Note: you will see entries named Tunnel adapter Teredo Tunneling Pseudo-Interface: we dont need to see that information - JUST the information above those entries

For Windows 8 or Windows 10

To open a Cmd Prompt or an Administrator Cmd prompt from the Desktop.
How to open an Elevated Command Prompt in Windows 8
Use Windows + X Keys together and choose Command Prompt (Admin) from the list.​

Or Right click on the windows icon - bottom left hand side - A menu appears - choose Command Prompt (Admin)[/indent]

For windows version, XP, Vista, W7

Hold the Windows key and press R
Now type CMD
Now press Enter to open a command prompt box (A new dialogue box - black with white font, will appear on screen ):​

In the command prompt window that opens, type the following command:

Note that there is a space before the /ALL, but there is NOT a space after the / in the following command.

ipconfig /all > network.txt & network.txt ​

It will export the results into notepad and then automatically open the notepad and display on your screen.

Now all you need to do is copy and paste those results into a reply here
to do that:
From the notepad menu - choose Edit - Select all
all the text will now be highlighted
Next
From the notepad menu - choose Edit - Copy

Now go back to the forum - goto the reply and then right click in the reply box and paste the results.
The results from the notepad should now appear in the forum reply.
------------------------------------------------------------------------

 

[Zelkovan]

Ipconfig from computer connected only via Ethernet:


Windows IP Configuration

Host Name . . . . . . . . . . . . : Julian
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Ethernet:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
Physical Address. . . . . . . . . : 94-DE-80-75-64-73
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::d090:f33c:999b:85a%4(Preferred)
Autoconfiguration IPv4 Address. . : 169.254.8.90(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.0.0
Default Gateway . . . . . . . . . :
DHCPv6 IAID . . . . . . . . . . . : 110419584
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-19-D0-B5-92-94-DE-80-75-64-73
DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1
fec0:0:0:ffff::2%1
fec0:0:0:ffff::3%1
NetBIOS over Tcpip. . . . . . . . : Enabled





IPconfig with a laptop connected via Wifi:


Windows IP Configuration

Host Name . . . . . . . . . . . . : WINDOWS-K2BJ1DN
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : hsd1.fl.comcast.net

Ethernet adapter Bluetooth Network Connection:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Bluetooth Device (Personal Area Network)
Physical Address. . . . . . . . . : C4-8E-8F-F6-4E-20
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Wireless LAN adapter Local Area Connection* 2:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft Wi-Fi Direct Virtual Adapter
Physical Address. . . . . . . . . : C6-8E-8F-F6-4E-1F
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Wireless LAN adapter Wi-Fi:

Connection-specific DNS Suffix . : hsd1.fl.comcast.net
Description . . . . . . . . . . . : Dell Wireless 1560 802.11ac
Physical Address. . . . . . . . . : C4-8E-8F-F6-4E-1F
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2601:586:4702:6f69:61f8:7e78:802b:2a53(Preferred)
Temporary IPv6 Address. . . . . . : 2601:586:4702:6f69:5c3f:38d3:7119:9628(Preferred)
Link-local IPv6 Address . . . . . : fe80::61f8:7e78:802b:2a53%3(Preferred)
IPv4 Address. . . . . . . . . . . : 10.0.0.201(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Sunday, February 28, 2016 12:27:44 PM
Lease Expires . . . . . . . . . . : Monday, March 7, 2016 12:36:18 PM
Default Gateway . . . . . . . . . : fe80::9e34:26ff:fe1e:717a%3
10.0.0.1
DHCP Server . . . . . . . . . . . : 10.0.0.1
DHCPv6 IAID . . . . . . . . . . . : 63213199
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1D-3A-ED-B4-9C-EB-E8-12-1A-C6
DNS Servers . . . . . . . . . . . : 75.75.75.75
75.75.76.76
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter Teredo Tunneling Pseudo-Interface:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2001:0:9d38:6abd:1c21:ef4:51c2:af4f(Preferred)
Link-local IPv6 Address . . . . . : fe80::1c21:ef4:51c2:af4f%8(Preferred)
Default Gateway . . . . . . . . . :
DHCPv6 IAID . . . . . . . . . . . : 318767104
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1D-3A-ED-B4-9C-EB-E8-12-1A-C6
NetBIOS over Tcpip. . . . . . . . : Disabled

Tunnel adapter isatap.hsd1.fl.comcast.net:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : hsd1.fl.comcast.net
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #7
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

 

[etaf]

how do you know its not the cord

because I've tried the cord on a different computer and it couldn't connect via ethernet and when I tried a different ethernet cord the same issue arose. When I tried it on the other computer it said that it was self-assigned an IP of 169.

So thats two different PCs and two different Cables tried - and not working

is that correct ?

have you powered off the router ?

 

[Zelkovan]

Yes, that's correct. I tried the ethernet cord using a laptop and disabling wifi on the laptop and it also couldn't connect to the internet via ethernet. Thinking it might be the cable, I got another ethernet cable and tried it on both PC's - didn't work on either of them either (I have two PC's, a laptop and a desktop. Laptop has wifi while desktop doesn't as it can only connect via ethernet).

I have tried powering off the router for a full minute, still did not solve the issue.

 

[etaf]

It would appear a problem with the router

it maybe worth resetting the modem/router - back to factory
what have comcast said ?

 

[Zelkovan]

Unfortunately they haven't been very helpful. The last I talked to them they just tried doing the good ol' resetting the modem trick, even though I explained to them that I had already done that. I'm going to try again and will update the thread in a bit, I guess.

 

[etaf]

how did they reset the modem ?

 

[Zelkovan]

I'm not quite sure "how", I just know that they are able to remotely reset the modem/router if you call them. I assume it's the same process of manually resetting the modem/router by pressing and holding the reset button in the back, but it is done remotely instead; I wouldn't know the how's of it, unfortunately.

 

[etaf]

OK, and you have already used the reset on the router itself

 

[Zelkovan]

Yup. Multiple times actually haha. Just called Comcast and it seems they will be sending out a technician to replace the modem/router, as everything they suggested I told them I already tried lol. So I guess I will update the thread when that happens. Thanks for helping out though!

 

[etaf]

your welcome

 

[Zelkovan]

So the technician won't come by for a bit, but I've got a question if anyone is still willing to help. I went into my router/modem's settings by typing the gateway adress in google chrome.

I noticed under online devices it listed everything that was connected to the internet through WiFi through DHCP. However, in the tab below it, titled offline devices, I noticed that my desktop (which is plugged in through ethernet and can't connect to the internet) was listed as offline with a reserved IP instead of a DHCP.

So, my question is, does that mean that the modem is recognizing that the computer is plugged in? If so, does that mean there is a setting to enable the computer to receive an IP? The only option I can (at first) seem to do is remove it from the list of offline devices, although I'm not sure what will happen if I do. Any help is still appreciated!

 

[Stancestans]

So the technician won't come by for a bit, but I've got a question if anyone is still willing to help. I went into my router/modem's settings by typing the gateway adress in google chrome.

I noticed under online devices it listed everything that was connected to the internet through WiFi through DHCP. However, in the tab below it, titled offline devices, I noticed that my desktop (which is plugged in through ethernet and can't connect to the internet) was listed as offline with a reserved IP instead of a DHCP.

So, my question is, does that mean that the modem is recognizing that the computer is plugged in? If so, does that mean there is a setting to enable the computer to receive an IP? The only option I can (at first) seem to do is remove it from the list of offline devices, although I'm not sure what will happen if I do. Any help is still appreciated!

If you actually reset the router, why does it still have an ip address reserved for the desktop? Resetting it should clear all settings to default, including reserved IP addresses in DHCP server settings.

 

[Zelkovan]

If you actually reset the router, why does it still have an ip address reserved for the desktop? Resetting it should clear all settings to default, including reserved IP addresses in DHCP server settings.

I'm not sure, honestly. I'm assuming the reset button on the modem actually does all this, although at this point I don't know anymore. What's also weird is that under the gateway address it says that the ethernet is up and running and the lights on the modem/router and blinking green.

Should I try a long power cycle on the modem, if that will do anything? I've already tried it, but hey, might work this time I guess. At this point i'm all out of options and I have to wait a few days for the technician...

 

[Stancestans]

I'm not sure, honestly. I'm assuming the reset button on the modem actually does all this, although at this point I don't know anymore. What's also weird is that under the gateway address it says that the ethernet is up and running and the lights on the modem/router and blinking green.

Should I try a long power cycle on the modem, if that will do anything? I've already tried it, but hey, might work this time I guess. At this point i'm all out of options and I have to wait a few days for the technician...

Yeah, that's exactly what the reset button is for. You have to long press it while the modem is on, until it restarts (lights should change as if you just did a power cycle).

 

[Stancestans]

Yeah, that's exactly what the reset button is for. You have to long press it while the modem is on, until it restarts (lights should change as if you just did a power cycle).

Update
My previous post isn't clear enough and can cause confusion. To reset the XB3 to factory defaults you must long press the reset button for more than ten seconds, after which the device will restart. A short press (1-2 seconds) simply restarts the device, and doesn't reset the settings to defaults.

What's also weird is that under the gateway address it says that the ethernet is up and running and the lights on the modem/router and blinking green.

Which lights exactly? The LEDs on the ethernet ports at the back or the lights in front? Perform a reset one more time (long press reset button for more than 10 seconds), let it restart and boot. The ON, US/DS and Online LEDs in front should all be lit (not blinking) after a brief moment. Network names (SSID) 1 and 2 should be back to default (see label on the product for default names, passwords etc).

 

[Zelkovan]

Which lights exactly? The LEDs on the ethernet ports at the back or the lights in front? Perform a reset one more time (long press reset button for more than 10 seconds), let it restart and boot. The ON, US/DS and Online LEDs in front should all be lit (not blinking) after a brief moment. Network names (SSID) 1 and 2 should be back to default (see label on the product for default names, passwords etc).

I was referring to the LEDs on the ethernet ports at the back. They are glowing green, which means (from what I can guess) that it is reading the ethernet port being plugged in, which is why I'm puzzled about this whole situation.

Also, I did as you said with a long reset for holding it more than 10 seconds, but it didn't seem to reset it to factory defaults. The SSID and password are still the same (meaning the ones we changed them to). Hasn't fixed the issue either, unfortunately.

 

[Stancestans]

I was referring to the LEDs on the ethernet ports at the back. They are glowing green, which means (from what I can guess) that it is reading the ethernet port being plugged in, which is why I'm puzzled about this whole situation.

Also, I did as you said with a long reset for holding it more than 10 seconds, but it didn't seem to reset it to factory defaults. The SSID and password are still the same (meaning the ones we changed them to). Hasn't fixed the issue either, unfortunately.

The LEDs on the ethernet port(s) are supposed to light up if a device is connected to any of them, and they'll blink if data is being sent/received through them.

The modem is not resetting via the reset switch. This could be an indication of hardware failure, more reason why it should be replaced. Can it be reset through its software? See if there's a reset to factory defaults option on its Web management interface. I didn't find any information about that on the user guide, but I expect it to be available. Try that option and see if it resets. If this fails too, you'll have to stick to WiFi and await for it to be replaced. Alternatively, you can try setting a static IP address on the PC and see if you have connectivity:

IP=10.0.0.210
subnet mask=255.255.255.0
gateway=10.0.0.1
Dns 1=8.8.8.8
Dns 2=8.8.4.4

 

[Zelkovan]

The LEDs on the ethernet port(s) are supposed to light up if a device is connected to any of them, and they'll blink if data is being sent/received through them.

The modem is not resetting via the reset switch. This could be an indication of hardware failure, more reason why it should be replaced. Can it be reset through its software? See if there's a reset to factory defaults option on its Web management interface. I didn't find any information about that on the user guide, but I expect it to be available. Try that option and see if it resets. If this fails too, you'll have to stick to WiFi and await for it to be replaced. Alternatively, you can try setting a static IP address on the PC and see if you have connectivity:

IP=10.0.0.210
subnet mask=255.255.255.0
gateway=10.0.0.1
Dns 1=8.8.8.8
Dns 2=8.8.4.4

Yeah, the Ethernet ports are green and blinking when the cord is plugged in from the desktop. I CAN reset to factory defaults through the web, although I'm afraid it may shut down the WiFi for the house, as I'm not the only one who uses it, in the off chance that something goes wrong.

Guess i'm waiting for the technician then.