Problem with Cradlepoint IBR900-600M

[scuba_steve999]

Hello!

I'd like some help troubleshooting an issue I have with a Cradlepoint IBR900-600M. The problem I have is almost identical to this help article from Cradlepoint: https://customer.cradlepoint.com/s/arti ... e-Internet

The symptoms are identical except when the problem is occurring (unable to connect to the internet), I can still ping both 8.8.8.8 and www.google.com. Both successfully ping with latency in the 30-50 millisecond range.

I tried to change the MTU value per the advice in the article but that has not helped. What else can I try? I've talked to Cradlepoint support multiple times about this issue and they come up empty.

The reason I am 99% certain it is an issue with the device is that when I reset the modem on the router, the issue is resolved immediately. I am using a Verizon SIM, and have a great signal (consistently get 50mbps down & 25 mbps up).

I am attaching a section of the log. It appears that there is some DHCP renewal happening, but I have no idea what that means.

Thanks for any guidance!

[Didneywhorl]

Has it previously worked? Where did the SIM come from? Have you set the TTL value to 117? or tried 65?64?

I wish I was much more familiar, but I do not have a CP router ;/

[JimHelms]

Hmm... This may be too simple of a fix, but do you have the interface Connection State for the modem set for Always on?

Always on.png

[scuba_steve999]

I'm traveling now but I'll take a look when I'm back with the device. Thanks for the suggestion!

Sim is from UnlimitedIRL. I've always had this issue. CP even sent me an RMA and the problem persists after replacement. I have a peplink BR 1 mini on order to see if that has the same problem.

I can also try the TTL tweak, but I am curious why that would make a difference?

[Didneywhorl]

TTL tweaking is generally to trick the network into thinking you are using a phone, but it is largely dependent on the network/carrier. I think the carrier its most useful for is Tmobile. I'm not sure if Verizon scans for TTL values, as Ive never dealt with them myself. I've only seen posts of others that suggest it, and have yet to have someone deem that incorrect info.

[scuba_steve999]

Follow up to this thread. I'm trying to isolate the problem so I purchased a peplink BR1 mini to see if the problem still occurred, and it does.

What is interesting in this case is that the problem comes and goes when connected to the peplink. In one span of time some things will connect but then others won't. Then some time passes and everything will work without me having done anything.

Hoping this makes sense to someone because I am olout of ideas for how to troubleshoot! Any advice?

[BillA]

Follow up to this thread. I'm trying to isolate the problem so I purchased a peplink BR1 mini to see if the problem still occurred, and it does.

What is interesting in this case is that the problem comes and goes when connected to the peplink. In one span of time some things will connect but then others won't. Then some time passes and everything will work without me having done anything.

Hoping this makes sense to someone because I am olout of ideas for how to troubleshoot! Any advice?

Since you're having the same issue using both devices, it would point to a service issue rather than hardware. Here's a list of various tweaks you can try in order to narrow down the issue. Remember each one is easily un-doable.

1. The first thing I would try, is to connect a mobile phone to your router via WiFi instead of a pc (assuming there's a DNS issue with your pc). If the phone connects while the pc can't, then you have just narrowed it down to your pc.
If it turns out to be a pc issue, then tun this script to clear the DNS cache among others, it can't hurt. Reboot both the pc and your router, then test it again.
Quick_Network_Reset.ZIP
https://wirelessjoint.com/download/file.php?id=1385

2. Since you can ping 8.8.8.8 even when unable to access web sites, it could point toward a DNS issue where your computer is unable to resolve URL's to IP addresses. You could try changing the DNS server in your device to 9.9.9.9 and even in your pc (I have changed both in my setup, it's a well knows DNS server). To change it in your pc, go to Network Settings > Change Adapter Settings > right click on your WiFi or Ethernet adapter, properties > disable IPv6, and for IPv4 "Use the following DNS servers" change it to 9.9.9.9 under both "Preferred" and "Alternate DNS servers".

3. Last but not least, while using the DNS servers in step 2, try these two MTU values: 1350 and 1400 set both in your router on pc. Additionally you could also run a quick TTL test without having to change it in the router, in a CMD prompt on your pc just copy and paste each line one by one. You can also try these two different values: 64, 117. Remember, this will only affect your pc.
netsh int ipv4 set global defaultcurhoplimit=65
netsh int ipv6 set global defaultcurhoplimit=65

Try to test each tweak thoroughly by running it for a day, without jumping to conclusions too quickly.
Let us know your test results.

[scuba_steve999]

I have found that if I run a VPN connection this problem goes away! Any idea why that may be?

[BillA]

I have found that if I run a VPN connection this problem goes away! Any idea why that may be?

A VPN masks (encrypts) all the traffic from Computer > Router > Carrier, to make it look like random data.
The two most common ways carriers try to limit you data usage, is either by TTL or UA.
Since you've already tried the TTL settings, then likely your carrier is using UA (User Agent) filtering (or both), that's why I suggested earlier to test your connection with a phone instead of a pc.
Out of curiosity, try to disable the VPN temporarily, connect your mobile phone to the router's WiFi, then go to a couple of different websites on your mobile phone. If it works, then you don't need a full blown VPN which slows down your connection and costs money every month. Instead, you could use a free UA spoofer for desktop Chrome or other browsers as posted here > https://wirelessjoint.com/viewtopic.php?p=4674#p4674
If it doesn't work, then you will have to use a VPN due to the more advanced stateful packet filtering your carrier employs.

[scuba_steve999]

Since you're having the same issue using both devices, it would point to a service issue rather than hardware. Here's a list of various tweaks you can try in order to narrow down the issue. Remember each one is easily un-doable.

1. The first thing I would try, is to connect to your router using a mobile phone rather than a pc at the moment when the pc is failing to connect (let's assume there's a DNS issue with your pc). If the phone connects even when the pc can't, then you have just narrowed it down to your pc. If it turns out to be a pc issue, then tun this script to clear the DNS cache among others, it can't hurt.
Quick_Network_Reset.ZIP
https://wirelessjoint.com/download/file.php?id=1385

2. Since you can ping 8.8.8.8 even when unable to access web sites, it could point toward a DNS issue where your computer is unable to resolve URL's to IP addresses. You could try changing the DNS server in your device to 9.9.9.9 and even in your pc (I have changed both in my setup, it's a well knows DNS server). To change it in your pc, go to Network Settings > Change Adapter Settings > right click on your WiFi or Ethernet adapter, properties > disable IPv6, and for IPv4 "Use the following DNS servers" change it to 9.9.9.9 under both "Preferred" and "Alternate DNS servers".

3. Last but not least, while using the DNS servers in step 2, try these two MTU values: 1350 and 1400 set both in your router on pc. Additionally you could also run a quick TTL test without having to change it in the router, in a CMD prompt on your pc just copy and paste each line one by one. You can also try these two different values: 64, 117. Remember, this will only affect your pc.
netsh int ipv4 set global defaultcurhoplimit=65
netsh int ipv6 set global defaultcurhoplimit=65

Try to test each tweak thoroughly by running it for a day, without jumping to conclusions too quickly.
Let us know how it went.

#1: I think I can safely rule out #1 here. Phones/tablets/PCs all exhibit the same behavior. I've tried setting phones and PCs to use Google DNS (configured on the devices) and the issue still occurs.

#2: Pinging and resolving URLs generally seems to work OK (except during the error state). Even when the error state is occuring I can resolve URLs when doing things like

Code: Select all

ping www.google.com

#3: Per Cradlepoint's instruction I did try setting the MTU value lower on the cradlepoint. That had no effect.

[BillA]

#1: I think I can safely rule out #1 here. Phones/tablets/PCs all exhibit the same behavior. I've tried setting phones and PCs to use Google DNS (configured on the devices) and the issue still occurs.

#2: Pinging and resolving URLs generally seems to work OK (except during the error state). Even when the error state is occuring I can resolve URLs when doing things like

Code: Select all

ping www.google.com

#3: Per Cradlepoint's instruction I did try setting the MTU value lower on the cradlepoint. That had no effect.

I think your might be having two concurrent issues here, one is the carrier filtering, and also some random modem outage. Anyway, as a final test, try to ping the google DNS server using the IP address instead of the domain name with the VPN off, once before the error state and during the error state.

The following should work with or without the VPN on, but fail during a modem outage.
ping 8.8.8.8

The following should fail without the VPN on and/or during a modem outage.
ping google.com

If you don't want to go the VPN route, your may consider switching to another carrier if that's even possible.