Internet Connection Lost

[afg1]

I am having a frustrating problem where I lose internet connection with my LB1120 modem once or twice a day.  I have it set up with a Ubiquiti Networks Router ER-X.    Mobile carrier is AT&T.  If I log into the modem admin when this happens it still shows that I have an internet connection, but I do not.  Even if I connect a device directly to the modem with an ethernet cable I don't have internet access.  I have tried a new SIM card and that didn't fix the issue.  One caveat is that if I the device I am using is connected using a VPN I still have internet access.   But any other device not connected through a VPN at that moment does not have internet access.  The only solution is to reboot the modem which immediately fixes the issue. 

Is this a modem issue, a carrier issue, something else?

[afg1]

So I've tried a new modem and this did not resolve the issue.  My provider said that because I can maintain a connection using a VPN the issue is likely due to one of the reasons listed below.  They want me to try to isolate the device that may be causing the problem.  I ran scans on my computers for viruses, etc. and haven't found anything yet.  Does this sound reasonable?  Has anyone ever heard of this or experienced this issue?

Connections to:
Public TorrentTrackers
Abuse / Illegal Sites
Illegal Drug Sites
Malware, Spyware, or other malicious activity that could be damaging to the network or end user
Port Sniffing on the network

[Rumsey]

I’ve been having the same problem with mine for about a month now. I think it’s a software program. I’ve had mine for about four years now and never had an issue till recently. I’ve tried everything to fix it. Rebooting it fixes it

[afg1]

Thanks for the reply.  I would think that if this were a software issue we would see more discussions around this in this forum.  But I guess we just wait to see if others comment or Netgear has a software update.

[afg1]

One other detail on this is that if I am connected to a Zoom meeting it will continue to work and also Youtube videos will play.  But other websites will not load.

[icaruspony]

I think I know what is happening.  It happened to me, and I figured it out with a little investigating.

Let the problem return (where the connection is not working).  DO NOT REBOOT OR FIX IT.  While the problem is still present, do the following tests:

1. Can you ping, still? (yes/no)

ping portquiz.net

2. Can you access portquiz.net on port 80? (yes/no)

http://portquiz.net:80

3. Can you access portquiz.net on port 443? (yes/no)

https://portquiz.net:443

4. Can you access portquiz.net on port 666? (yes/no)

http://portquiz.net:666

5. Which VPN were you using that worked?  ______________________

6. What port # do you connect to this VPN server on?  _______

7. Are you on an AT&T Connect Car Plan or an AT&T Ipad plan? _______

This will help you figure things out.  I suspect you will be able to ping and will be able to connect to 666, but you will not have connectivity to 80 or 443, and I suspect your VPN is not using 80 or 443.

[afg1]

Thanks @icaruspony for the reply.   Please see below.

Pinging portquiz.net [52.47.209.216] with 32 bytes of data
Reply from 52.47.209.216: bytes=32 time=113ms TTL=44
Reply from 52.47.209.216: bytes=32 time=121ms TTL=44
Reply from 52.47.209.216: bytes=32 time=116ms TTL=44
Reply from 52.47.209.216: bytes=32 time=104ms TTL=44

Ping statistics for 52.47.209.216:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 104ms, Maximum = 121ms, Average = 113ms

Correct, I was only able to connect to port 666.

I've successfully held a connection using several VPNs.

- My work VPN(Cisco AnyConnect) - not sure what port number, but this VPN needs to be connected before I lose my internet connection.  Other VPNs can be turned on after the connection drops to regain a connection.  I don't know if this is significant, but when initially connecting it always connects and disconnects 3 or 4 times before successfully keeping the connection.

- ProtonVPN - according to support page it says "The ProtonVPN app’s default port is 1194 for UDP (which is the default port for OpenVPN) and 443 for TCP. However, the app is configured to work with other ports for both UDP and TCP. These ports are backups in case the main ports are blocked. If the app detects a block, it will search among the backup ports and use the port that offers the best performance. "
- Speedtest.net -  Speedtest VPN uses the OpenVPN protocol on Android and the IKEv2 protocol for iPhone (iOS). The following ports are used for each specific protocol on the two different platforms:

Android

The OpenVPN protocol uses the TCP or UDP protocols on port 443.

iOS
The IKEv2 protocol uses UDP port 500.

So what would be the next steps to resolve this issue?

[icaruspony]

This is intentional by AT&T for Connected Car plans (and maybe Ipad plans). They figure if you are in a car, you should be moving from tower to tower.

AT&T checks at (y) time intervals if you have yet used (x) amount of data on that specific session (connection to a tower on a band). If you have exceeded the limit, all outbound 80 and 443 ports are blocked. The web and many apps and some VPNs use these two ports. To reset this, you must start a new session (reboot, turn data on/off, switch bands, or move to new tower).

Of course if there was a tunnel from your network to the internet that did not use port 80 or 443 then a stalled/dead port 80 and 443 would remain irrelevant as all your packets get encapsulated and pushed through a different unhindered port... HMMMM...

Ask all your VPN providers for alternate ports than 80 and 443. They typically have alternative ports listening.

[afg1]

@icaruspony As I mentioned, connecting with a VPN is the only solution that works, so not sure why we would need to change anything there. The other solution is rebooting the modem. Is there a way that I can use this internet service without doing one of these two things?
Attached is the current provider I use for internet service. I had the same issue with the previous provider.

Thanks.

[icaruspony]

Options are VPN, reboot, toggle data on/off, switch bands, or switch towers.

[afg1]

@icaruspony so I use this service for home internet. There is only the one tower near my home, so that wouldn’t work.
How do you toggle data on/off?
Does switching bands mean switching ports. How does one do that?

[icaruspony]

In the web interface there is a toggle switch for data. Someone on here even posted a python script that you can load into a separate router with entware or optware to automatically toggle data off and on when connection is lost.

By default, there are two bands: WCDMA and LTE All. On a side note, some people have used USB and telnet to add new bands to this list that will lock your device to specific band(s). That way, it can be forced to connect to the FASTEST band instead of the STRONGEST band.

[icaruspony]

I think a better question to ask is, why don't you want to connect to a VPN 24/7? Whatever your concerns are, I can probably address.

[afg1]

@icaruspony A few questions on use of VPN....

Should one be added to each device?  Any recommendations?

What about at the network level?  I have a Ubiquiti Networks Router ER-X

My son said using a VPN affects online gaming.  Is there a workaround?

[icaruspony]

Putting a VPN on each device isn't a very efficient method. It is better to put it on a powerful router with enough CPU to be able to handle the encryption. That can be a PC or a router with built in hardware encryption (like Asus AC86U). You have to research the encryption speed of that router.

On the other hand, the focus of using this VPN is to use the VPN as a proxy so that you can redirect traffic to another port (not really for privacy/encryption, after all, you would be happy to have had this working without any VPN or encryption, right?)

So you can consider a weaker, less CPU intensive VPN protocol, such as PPTP, which has almost no encryption. This would be faster and less hardware demanding and would direct all your traffic through a good port, as required to fix this problem. But it would also be decrypt able by others. However, not using a VPN is no more secure than this, anyway, so this isn't necessarily a drawback compared to the way you normally go online without any vpn encryption.

Bear in mind, with "no VPN" versus the weak "PPTP VPN" versus a strong "OpenVPN", for the important, sensitive data (credit card, debit card, passwords, etc) your web browser and apps should be doing their own encryption, separately. This means even without a VPN (or with a weakly encrypted VPN protocol), at least the most sensitive data is encrypted strongly by the browser/app anyway. Sensitive data is never left unencrypted. Having a strong VPN protocol like OpenVPN is like wearing two bulletproof vests at once instead of wearing one bulletproof vest.

As for gaming speeds, you just need to look out for two things. One is a hardware bottleneck, like a router whose CPU can keep up with the packets flowing through the connection as it struggles to encrypt them, with the CPU pegged at 100%, and slowing down the network. This is resolved as mentioned above... get a beefy CPU router with hardware encryption that can keep up with your speeds while the CPU never hits 100% and it can keep up easily... or... use a weaker encryption protocol such as PPTP so that your weak router CPU has an easy time keeping up.

The second speed concern is added travel distance for your packets. The packets must go from your location to the VPN node, first. Then it travels to its destination. The same is true with return data, in reverse.

Think of it like a geographical map (even though in a network sense, geography and lower distance in miles is not always the "fastest path") . Imagine if you are in New York and your VPN endpoint is 2500 miles away in California. If you are contacting a website in California, this is fine, the data travels 2500 miles to the VPN node, then does a short hop, skip, and a jump to the website right there next door in California. The VPN did not add any significant distance. But what if you want to connect to a website in NY across the street from you? Normally, this would be a very fast, short distance communication across the street. Except your packets must travel 2500 miles to the California VPN node, then travel 2500 more miles to get back to New York to that website across the street from you. That's 5,000 miles round trip, which should have been just 30 feet.

This is why you choose a VPN node that is "close" to you. This creates a short distance pit stop for your data on the way out of town, which adds very little distance to the trip. It adds a little ping time, but potentially still fine for gaming, if you choose the right VPN node. As well as making sure your router cpu can keep up, as I mentioned before.

I also want to add that world geography doesn't always match "network geography". For me, AT&T routes all my traffic to an AT&T exit node on the other end of my state. So for all intents and purposes my internet connection is over THERE... not HERE where I am. This is why I use VPN nodes in THAT city and not MY city.

I know this is confusing, but let's make up a scenario and say you live in Las Vegas but your ISP tunnels all of your data out of Los Angeles. You would know this by looking up geographically where your AT&T connection (without a VPN) is located with whatismyip.com

If you chose a VPN local to you (Las Vegas), then AT&T would pipe your data to their Los Angeles datacenter, then the data would have to travel a long way back to Las Vegas to your chosen local VPN. So you want your VPN to be local to the AT&T exit point (as told by whatismyip.com), which may or may not be physically where YOU are. In my case, my AT&T exit point is 450 miles away from me, so I save 450 MILES of added data travel by choosing a VPN nearby the AT&T exit point way over THERE instead of making all my data make a pit stop back to HERE before going where it's going.

[adonisan]

This seems to be a problem with AT&T. Port 80 and 443 eventually stop working and require a reboot.

https://forums.att.com/conversations/other-phones-devices/att-transparent-proxy-not-stable-hanging-c...