Connection Problem: Router's ping works, but cmd's doesn't

Jwaynw

n00b
Joined
May 9, 2013
Messages
8
Hello all! Greetings from Argentina!

I have a TP-link router model TL-WR841ND V8 that seems to have the WAN port malfunctioning. The wireless is working correctly, but I can't connect to the internet (wired nor wireless) with it and I wanted to try it all before throw it to the garbage (or use it as switch or wi-fi repeater).

Let me say that the cables are correctly connected and the configuration is correct since I can connect to the internet with another router (Belkin)

At first I was getting a "WAN port is unplugged!" message and I wasn't getting IP.



But after I tried a hard reset, firmware update and power cycle, I finally got an IP.



However, I still cannot access the internet. The strange thing (at least to me) is that when I use the diagnostic ping inside the router's web, most of the times I get correct reply (other times I get "time out" or "could not find the host").



But when I tried to ping the same host from a command line, I only get "destination host unreachable".



Is there any other config I could try or can you confirm this is a HW problem and I should grab the trash can?

I hope anyone can help me with this.

Thanks in advance!
 
Try doing a tracert so that you can see how far you're getting.

Also, is there a modem? If so, have you tried plugging directly into it to see if the problem persists?
 
Thanks for your answer.

Yes, there is a cablemodem. If I connect my desktop directly to the modem everything works OK. And like I said in my post, I've also had tested with another router (Belkin) and everything works well too.

I think the settings are OK, otherwise I wouldn't get an IP from my ISP.
 
I'd plug the modem back into the router, verify the WAN port is up and getting an IP and able to ping the outside (Internet). Go to the cmd prompt and type ipconfig make sure it's showing an IP address from the routers DHCP pool. If not (and I'd probably do this regardless just to be sure) type ipconfig /release, then type ipconfig /renew. Perhaps restart the computer just to be sure and you might have to do a restart after releasing the IP.

If the WAN port is working it could just be an IP thing. Your machine could be thinking it's still plugged into the modem (before it was working) or have a default Local-Link Address from the OS when it was unable to connect.

If the WAN port is actually working now and can ping the outside world then there is no reason why the internal should suddenly just stop working unless some settings got screwed up during the hard reset/firmware upgrade. I'd try the above steps first and see if that does anything.
 
Many times you have to power cycle the cable modem when changing routers/devices.
 
Liger88 & Spartacus thanks for your answers.

I'd plug the modem back into the router, verify the WAN port is up and getting an IP and able to ping the outside (Internet). Go to the cmd prompt and type ipconfig make sure it's showing an IP address from the routers DHCP pool. If not (and I'd probably do this regardless just to be sure) type ipconfig /release, then type ipconfig /renew. Perhaps restart the computer just to be sure and you might have to do a restart after releasing the IP.

If I plug my PC directly to the modem, everything works well (I get an IP, ping outside and surf the web)
If I plug my PC to the Belkin router, and the Belkin router to the modem, everything works well (I get an IP, ping outside and surf the web)

If I plug my PC to the TP-Link router, and the TP-Link router to the modem, I don't have internet (I get an IP, ping outside works ONLY from the router's web, ping outside from cmd doesn't work and I couldn't surf the web)

I had already verified that the IP from ipconfig was correct (inside the pool, gateway is the router). I also had tried releasing and renewing, restarting, and even shutting the PC.


If the WAN port is working it could just be an IP thing. Your machine could be thinking it's still plugged into the modem (before it was working) or have a default Local-Link Address from the OS when it was unable to connect.

Wouldn't this be happening with the Belkin router too?

If the WAN port is actually working now and can ping the outside world then there is no reason why the internal should suddenly just stop working unless some settings got screwed up during the hard reset/firmware upgrade. I'd try the above steps first and see if that does anything.

The problem was prior the hard reset and the firmware update. I performed those things just to see if it solved the problem. I did the FW update from the router's web and finished successfully.

Many times you have to power cycle the cable modem when changing routers/devices.

I did a power cycle several times with no success. This is not needed with the Belking router though, wich works plug and play.

Since the LAN ports and the wi-fi is working correctly, and the settings works with another router, I thought this was a problem with the WAN port exclusively. Is there any circuit that might be burned (because of a storm) regarding only the WAN port? Can this port simply be replaced?

Thanks for your insights.
 
The power cycle on the cable modem has more to do with forcing the cable modem to let go of the MAC address of the last router/device connected. Not related to plug & play.

If the Belkin works, then the TP-Link should work too. Make sure you are using the same WAN setup on the new router as the old one that works. The type of connection, (DHCP, Static, PPPOE) is critical.
 
Thank you for clarifying that matter. When I said "plug and play" what I meant to was that the Belkin router works without the need that the modem lets go the MAC address (of the PC or TP-LINK router). I had read that some ISP don't let to connect with more than one MAC, but it is not my case since I didn't need to clone my PC MAC address in the Belkin router in order to work. Nevertheless, I tried to clone the MAC address in the TP-LINK with same results: I get an IP, with no internet connection.

All the settings were copied from the Belkin router to the TP-LINK router. The connection type is dynamic, DNS from ISP.

I repeat the question in the hope that someone can answer it: since LAN ports and wi-fi are working correctly, and the settings works with Belkin router, Could this problem be narrowed to the WAN port exclusively? Is there any circuit that might be burned (because of a storm) regarding only the WAN port? Can this port simply be replaced?

Thanks for your help.
 
provide an ipconfig and a tracert to yahoo.com or google.com, from your PC, when you have your PC plugged in to the TP-LINK router.
 
TPLink is actually very solid for me as a basic access point.

It is probably bad. They cost like $5 go buy another and be happy.
 
provide an ipconfig and a tracert to yahoo.com or google.com, from your PC, when you have your PC plugged in to the TP-LINK router.

Here is the info you requested: http://tny.cz/6ce2181a

Additionally, here is the results for the same commands with the Belkin router (http://tny.cz/9df7bfde) and the results connected to the cablemodem directly (http://tny.cz/88c3648c)

Since the ping and the tracert don't work from the command line, here are the results from the TP-LINK router's web (were they do work):

Ping yahoo.com



tracert yahoo.com



TPLink is actually very solid for me as a basic access point.

It is probably bad. They cost like $5 go buy another and be happy.

I'm from Argentina and here you will buy it USD 44 as cheap. With that money, I could buy 46 Coke cans :D.

Nevertheless, I already have the Belkin router, I just wanted to confirm the TP-LINK router had the WAN port broken.
 
Here is the info you requested: http://tny.cz/6ce2181a

I don't know Spanish, but I'm guessing "Puerta de enlace predeterminada" is Default Gateway?

Dirección IP. . . . . . . . . . . : 192.168.2.2
Máscara de subred . . . . . . . . : 255.255.255.0
Puerta de enlace predeterminada :

For whatever reason, your computer is not getting a Default Gateway. Because it doesn't have a default gateway, it doesn't know how to "leave" the local network.

DHCP habilitado. . . . . . . . . : No
Autoconfiguración habilitada. . . : Sí

This tells me your network adapter is not configured to receive an IP via DHCP.

Open an elevated command prompt
enter:
Code:
netsh int ip reset reset.logl
netsh winsock reset

Then reboot.
 
You are correct "Puerta de enlace predeterminada" means Default Gateway. Sorry not clearing that up but I thought it would be clear since it's the same order as the english results.

I missed that. But when I tested this again, I was able to obtain a default gateway and the ping start working from the command line. However, when I tried to load google page through the browser, the connection restarts.

My network is configured to receive an IP address. In TCP/IP properties the options "Obtain an IP address automatically" and "Obtain DNS server address automatically." are both selected. You can confirm that by looking at the IP I get when I connect my PC directly to the cablemodem. (http://tny.cz/88c3648c)

I executed the commands you pointed, but the results are the same. Sometimes I get blank default gateway, and ping doesn't work from cmd, and sometimes I do get a default gateway, the ping from cmd does work (intermittently) but as soon as I tried to connect to a web using the browser, the connection resets.

Like I said in previous post, I think that we can discard this is a settings problem, since I'm able to connect without problem with another router with the same setting as the TP-Link's. I even tried the TP-Link in another PC, and in a LiveCD, without any luck.

I'm going to try to configure the LAN port as WAN port. Here is a tutorial on tp-link site that explains how to do it with another model: http://www.tp-link.com/en/article/?faqid=344

Unfortunately, my router doesn't support that feature, so I guess I will have to use openWRT firmware. Here are some guidelines of some people with the same problem I'm facing:

https://forum.openwrt.org/viewtopic.php?id=16148
https://forum.openwrt.org/viewtopic.php?id=13441

I'm going to read a lot since I'm new with this kind of stuff, but I'm very confident this will help me.

Thanks for all your help.
 
check for a newer firmware maybe?
since your computer receiving a Default Gateway, via DHCP from the TP-Link router, is hit or miss, that's (most likely) an issue with the router's software; not hardware.

possibly even see if you can re-flash the current firmware version if it's already at the latest.
 
I've already tested with all the firmwares available in TP-Link site. This is definitely a hardware problem, since is working with another router, and I've tried all the posible settings and all the posible oficial firmwares, I'll move on and try an unofficial firmware like OpenWRT in order to assign one of the LAN port as the WAN port.
 
I've already tested with all the firmwares available in TP-Link site. This is definitely a hardware problem, since is working with another router, and I've tried all the posible settings and all the posible oficial firmwares, I'll move on and try an unofficial firmware like OpenWRT in order to assign one of the LAN port as the WAN port.

sorry if I wasn't clear; it's an issue with the router's software/firmware.

The issue is certainly not with your computer, I agree. But I don't believe it's a hardware issue with the router.
 
But I don't believe it's a hardware issue with the router.

Sorry, but I don't agree. The WAN port is the only thing is not working (actually, it is working but intermittent), and several people had reported the same problem (a storm fried WAN port and everything else is working). You can see it here:

Broken WAN port after storm, how to change LAN port into WAN
WRT54GL: Broken WAN port, possible to use LAN port instead?
How do I assign the internet port to port 3?
Change WAN Port on WRT54GL
TL-WR740n v4.2 how to change WAN port

The last two didn't mention a storm, but they had the same problem. If it was an issue with the router's software/firmware, How or what caused the issue? What is the issue? An wouldn't the issue be solved after a firmware upgrade? Please let us know in case someone have this issue in the future.

Anyway, in case someone in the future faces a similar problem, you can use one of the working LAN ports as the WAN port. If your router has the feature of working with VLANs from the web interface, you can use this guide as a reference. Otherwise, you should try a custom 3rd party firmware like DD-WRT or OpenWRT (you have to make sure your router is supported - DO IT AT YOUR OWN RISK). In my case, I installed OpenWRT firmware and then followed the steps depicted here, and additionally, I followed these missing steps. I did it for my router and it worked like a charm.

Thanks again for all your help.
 
Sorry, but I don't agree. The WAN port is the only thing is not working (actually, it is working but intermittent), and several people had reported the same problem (a storm fried WAN port and everything else is working). You can see it here

you're right.
I was thinking too far in to the lack of a default gateway being received by DHCP.
I could see a disconnect of the WAN port from the rest. Strange that it continued to receive an IP from the ISP though.
So chances are it may have been a 2-part issue.

Although if you read those links you posted, the ones that stated the issue were simply getting no link light on the WAN port. Slightly different issue than you, since you were getting an IP from your ISP; traffic just wasn't flowing from the LAN to the WAN. ;)

Glad to hear you were able to get it working though.
 
Back
Top