NR7101 nslookup works but ping doesn't and I can't browse the internet

KingJulian

Hi all, I have been struggling to get my NR7101 working again.

When it was working it was in router mode using manual apn settings. Then it just stopped working.

• I thought maybe it was a windows update, so I rolled that back, then I reset the pc entirely. 
• I also reset the NR7101 to factory. but it still doesn't work. 
• I re-uploaded a restore to the NR7101 from a save file I had when it was known to work and it still doesn't work. 
• I tried to use the diagnostics, and ping doesn't work, it says host Unknown Host or Unreachable Network! 
• When I try and browse the internet on my computer I get DNS could not be found or similar.

I might be completely wrong but I think there is something wrong with how the NR7101 is resolving DNS queries, but I have no idea what's wrong or how to fix it. I've tried setting static DNS, DNS Proxy or DNS from ISP, in NR7101 but nothing makes a difference. 

Could you help me please as it was working fine but for the life of me I can't get it working with what seems to be the exact same setup. I've tried to include as many screenshots as I can, if you need any more info ill post them aswell.

When it was working it was great I'm on 3mbps adsl, but this got me 300mbps and was just excellent so I want that back

Thank you. Tom

KingJulian

Also, something else I thought was weird was the time, I can't resolve the time as its not connecting to the internet, and the time is wrong in the NR7101. I know sometimes having the wrong time does weird things. I tried to set up an NTP sever on my computer so it can talk to that but it wouldn't speak to it and get an updated time. attached screenshot of the wrong time. also screenshot of the nslookup result that appears to be working which I forgot to include in last post. 

Bob_C

Hi Tom, 

I suppose that the Internet-bound traffic does not work at some point after you rebooted/reset the NR7101 last time even though the NR7101 still has a WAN IP address. 
The reason is because ping 8.8.8.8 do not have any response, the NR7101 is not time-synchronized either. 

The positive nslookup result could be a cache which reflected a previous successful record. 

I think we may go through a series of troubleshooting, which will need your input for checking the NR7101's behavior, testing some scenarios, and possibly remote sessions by Teamviewer or Anydesk. That being said, I would suggest that you contact our support team who can create a ticket for your case. 
Contact Support | Zyxel Networks

I have some quick questions for your case, it'd be good if you can clarify these questions and inform the support team and/or update here.

(1) How long have you been using the NR7101? Does this problem (ping 8.8.8.8 does not work) happen recently or does this problem exist from day 1 when you use the NR7101?

(2) Please turn on Network Monitor (Network Setting > Broadband > Cellular WAN > Network Monitor), click Apply, and see if it helps to recover the connection when the problem happens. 


(3) Please turn on local logging (Maintenance > Log Settings > Syslog Logging), tick WAN-DHCP, System, Cellular WAN, ESMD, click Apply. 



(4) Following (3), if the problem happens again, please go to System Log (System Monitor > Log > System Log), and export the log. 



Regards, 

Bob

Noddy

Hey Tom, you say "When it was working it was in router mode using manual apn settings. Then it just stopped working. "

Is is possible that the SIM card is corrupt in some way?  Your provider could ship you out a replacement in 1-2 days and you could try swapping it out.  Weird for it to just stop working.  It does just look like you have no connection.  Bob's suggestion about enabling the logging etc will help.

Have you confirmed the APN settings as well for your provider?  Or tried them back on Auto instead of manually defined?

Thanks.

Noddy

Bob, can you expand on what the network monitoring setting does please?  I to have it currently disabled, is it recommended to be enabled and if so why?

Thanks.

EDIT: Found it in the guide:

"Use this field to allow the Zyxel Device to try reconnecting to the base station if the cellular
connection is lost. After the third try, the Zyxel Device will reboot to try to reconnect with the base
station. The LED will blink red to indicate that it is rebooting."

KingJulian

Bob_C said:

Hi Tom, 

I suppose that the Internet-bound traffic does not work at some point after you rebooted/reset the NR7101 last time even though the NR7101 still has a WAN IP address. 
The reason is because ping 8.8.8.8 do not have any response, the NR7101 is not time-synchronized either. 

The positive nslookup result could be a cache which reflected a previous successful record. 

I think we may go through a series of troubleshooting, which will need your input for checking the NR7101's behavior, testing some scenarios, and possibly remote sessions by Teamviewer or Anydesk. That being said, I would suggest that you contact our support team who can create a ticket for your case. 
Contact Support | Zyxel Networks

I have some quick questions for your case, it'd be good if you can clarify these questions and inform the support team and/or update here.

(1) How long have you been using the NR7101? Does this problem (ping 8.8.8.8 does not work) happen recently or does this problem exist from day 1 when you use the NR7101?

(2) Please turn on Network Monitor (Network Setting > Broadband > Cellular WAN > Network Monitor), click Apply, and see if it helps to recover the connection when the problem happens. 


(3) Please turn on local logging (Maintenance > Log Settings > Syslog Logging), tick WAN-DHCP, System, Cellular WAN, ESMD, click Apply. 



(4) Following (3), if the problem happens again, please go to System Log (System Monitor > Log > System Log), and export the log. 



Regards, 

Bob

Hi Bob, 

Thank you very much for your help and thoughts.

I've been using the NR7101 for a few months now, and its been working great, then one day (the other day) it stopped working (I could no longer browse the internet when previously I could at excellent speeds ) so that got me looking into why, from there I found a few things that I thought might be the issue like the ping not working from the device out to the internet when it previously did, the nslookup working (which I thought was strange if ping doesn't work) and the time being off and not syncing at all. Those are just things I thought were weird but I might be barking up completely the wrong tree. So my problem is I can't use the device to access the internet when previously I could, it also used to be able to ping out to the internet and no longer can and the time was previously synced correctly. 

Ive turned on network monitor as suggested but hasn't made a difference to connectivity with the internet or ping out.

Thanks for explaining about nslookup might be in cache, I did do a few factory resets of the device so id have thought that would have cleared the cache? still ping doesn't work but nslookup does after the resets. 

Ive turned on syslog as mentioned as-well, shall I post the log here or in my ticket to support? 

Ive also raised a ticket with support, who suggested, not to use wifi as that's not for browsing, I already knew this though and wasn't using wifi it was just turned on, I use the cable to connect and have done when it was working for the last few months, I did turn wifi off though in the NR7101 just incase but its hasn't fixed the problem either. 

They also suggested upgrading the module firmware to the newest one which I have done, (I was 2 upgrades behind) so did them as instructed and in order but again this hasn't fixed the problem.

Ive just emailed them back letting them know that I've updated the module firmware and still no fix so await another round of trouble shooting steps. 

Thanks again for taking the time to help

Tom

KingJulian

Noddy said:

Hey Tom, you say "When it was working it was in router mode using manual apn settings. Then it just stopped working. "

Is is possible that the SIM card is corrupt in some way?  Your provider could ship you out a replacement in 1-2 days and you could try swapping it out.  Weird for it to just stop working.  It does just look like you have no connection.  Bob's suggestion about enabling the logging etc will help.

Have you confirmed the APN settings as well for your provider?  Or tried them back on Auto instead of manually defined?

Thanks.

Hi Noddy, 

Thanks as-well for taking the time to try and help. 

This is a good thought, nothing has changed up there but it could be this kind of thing as it feels like I've tried everything else, ill contact them and get a replacement sent and also try another sim I've got to see if its something to do with the card/contract or other corruption. 

Good thought about APN settings as-well although I have already tried that, I've double-checked the manual APN settings and also set it to auto but again still no joy and the problem persists. 

I'll try another sim/replacement though and let you know if it fixes it. 

thank you again 

Tom

Bob_C

Hi Tom, 

Few more questions about this case: 
Q1: What is the APN-in-use? Is there any APN change from your service provider's end? As Noddy pointed out, you may contact your service provider for these questions and requests. 

Q2: Please provide the first 5 digits of IMSI (the 5 digits from the left). You can find your IMSI on Cellular WAN Status (System Monitor > Cellular WAN Status). 


Q3: Is this SIM card a pre-paid service or a subscribed service?
 
Q4: So, after the problem happened the other day, even if you rebooted or reset the NR7101, the ping did not work right after reboot, is that correct?

----
Thanks for clarifying the NR7101's behavior, especially about nslookup. I think it's not about cache if you're rebooted or reset several times but still see positive nslookup results. 

In terms of the syslog, please provide it in the ticket to the support team. You may also attach it in this article or in a private message to me. 

Just try to understand as much as I could and see if I can find any clue about the root cause in parallel of the ticket handling.  

Regards, 

Bob 

Bob_C

Hi Noddy, 

Network monitoring includes periodic connectivity check and connection recovery. 

If the Internet connection has been stable while the feature is disabled, I think you may keep it disabled. 

If the Internet connection has been unstable, especially if the NR7101 frequently disconnects and does not recover, you may enable network monitoring. 

Regards, 

Bob

KingJulian

Bob_C said:

Hi Tom, 

Few more questions about this case: 
Q1: What is the APN-in-use? Is there any APN change from your service provider's end? As Noddy pointed out, you may contact your service provider for these questions and requests. 

Q2: Please provide the first 5 digits of IMSI (the 5 digits from the left). You can find your IMSI on Cellular WAN Status (System Monitor > Cellular WAN Status). 


Q3: Is this SIM card a pre-paid service or a subscribed service?
 
Q4: So, after the problem happened the other day, even if you rebooted or reset the NR7101, the ping did not work right after reboot, is that correct?

----
Thanks for clarifying the NR7101's behavior, especially about nslookup. I think it's not about cache if you're rebooted or reset several times but still see positive nslookup results. 

In terms of the syslog, please provide it in the ticket to the support team. You may also attach it in this article or in a private message to me. 

Just try to understand as much as I could and see if I can find any clue about the root cause in parallel of the ticket handling.  

Regards, 

Bob 

Hi Bob, 

APN is wap.vodafone.co.uk when set to manual and internet when set to automatic. 
IMSI is 23415 so vadafone uk I think that means. 
its a contract sim, and I've paid regularly and got another 7 months left on the contract. 
kind of, the unit just stopped letting me browse the internet, then I started doing things like rebooting but yes after reboot ping still didn't work.

The support team are looking at the syslog but say it might take a while so have asked me to try a different sim like noddy said, just dreading going up the pole, but ill do it this weekend and switch it over and try that. 

thank you! 

tom

KingJulian

Noddy/Bob, i might have the answer I called Vodafone, and I'm on an unlimited data plan, but they said that I had used the unlimited amount of data. I asked how that's possible and they said its not so I had to get the SIM card put it in a phone to get a code and then they are going to disconnect the card and reconnect it to their system to reset the data allowance. our family did download 9.1 TB last month though so I suppose its fair. ill let you know if it actually fixes the problem but I think that's it. thank you for your help though its much appreciated