[RT-AC68U] Can't connect to certain websites (USB 4G Dongle)

[Nazgulled]

Hi there,

I have an ASUS AC68U and I'm running Merlin's firmware version 374.43_2. Unfortunately I cannot upgrade to the latest version because my Internet connection comes from a USB 4G Dongle (which does not work with the latest firmware).

My problem is that I connect to certain websites. Occasionally, other websites take a while longer to connect (like google.com), but there's on particular website (www.fastnewsforum.net) which I can't get to connect. No matter what I do, it just won't connect.

I tried this on my laptop (wireless) and on my fixed PC (wired), both connected to the AC68U. With Firefox/Chrome it didn't work, the website just won't load (on Chrome it eventually times out, on Firefox, it keeps loading indefinitely). Surprisingly it loads on Internet Explorer (on both machines, wireless and wired).

Attempting to debug the issue, I took the USB 4G Dongle out of the router and connected directly to the laptop which is the one with the proper software required to connect the dongle to the Internet. It worked, I could open www.fastnewsforum.net with the dongle directly plugged on the laptop.

My conclusion is that the problem must be on the AC68U, not sure exactly what, maybe a configuration issue? Does anyone have any idea on what could be the issue?

 

[kvic]

Google "tcp mss".. Very likely u have to adjust tcpmss setting in your router's NAT

 

[Nazgulled]

Google "tcp mss".. Very likely u have to adjust tcpmss setting in your router's NAT

Can't find such setting anywhere on my router...

 

[kvic]

Can't find such setting anywhere on my router...

WebUI exposes basic/common settings. The rest you need to do it from command line..

http://www.linuxtopia.org/Linux_Firewall_iptables/x4700.html

 

[Nazgulled]

But why do I have to change that setting? Because I use a USB modem connection?

I've researched a bit about that setting, but I'm not really sure what value I should input for MSS. I see that MTU is also mentioned alot along with MSS, should I configure that value too?

Also, I found this: https://www.juniper.net/techpubs/so...guide-basic/tcp-maximum-segment-size-mss.html

Should I change the values through IPTABLES or like that link exemplifies?

 

[Nazgulled]

Can you or someone please explain a little bit further what exactly are the steps I need to take to sort this out?

The website in question I can now open most of the times. But in other situations, other websites take a lot to load and sometimes they even fail. And I'm talking about google.com, which I never experienced downtime with other types of connections.

My Internet is kinda unusable like this...

 

[kvic]

Sorry, I haven't looked into the details of tcp mss of that particular website... the website can load on my PC through Asus router. It might not be the issue that I initially thought.

One idea I have is to turn off firewall on your router, just for testing of a short period. Try as many problematic website as you can. It's possible that the automatic Path MTU discovery could have failed on the bad cases when you do it through router..

 

[Nazgulled]

Sorry, I haven't looked into the details of tcp mss of that particular website... the website can load on my PC through Asus router. It might not be the issue that I initially thought.

One idea I have is to turn off firewall on your router, just for testing of a short period. Try as many problematic website as you can. It's possible that the automatic Path MTU discovery could have failed on the bad cases when you do it through router..

Not sure if it's related but on newer firmware versions there's a setting for the MTU size when using a USB modem. There's no such option available on my current older firmware (maybe that can be changed through SSH? not even sure if it would help...) and like I said, I can't upgrade to a newer version, otherwise my modem will stop working.

I'll be sure to test that as soon as I get home...

 

[Nazgulled]

I currently have:

• Firewall » General » Enable Firewall: No
• Firewall » General » Enable DoS protection: No
• Firewall » IPv6 Firewall » Enable IPv6 Firewall: No

So far I've been experience (occasionally) some issues when using Firefox. It seems kinda random and sometimes I search for things (on the built-in search which defaults to Google) but the request never completes; when the search eventually returns, opening some links sometimes doesn't work either, it keeps loading and never finishes. In these situations, when the tabs are trying to load, I open Chrome, do the same search and it just works, any link I open seems to work much better on Chrome than Firefox.

This makes me think that my initial issue is now resolved (or at least much less frequent) and that the culprit is now Firefox since Chrome opens everything. This now falls out of the scope of these forums, but if you guys have any idea on what I might be the issue so that I can fix it, I'd really appreciate it because I prefer Firefox over Chrome.

 

[Puppa]

Watch out with IPV6 firewall off. There is no NAT on IPV6 to offer even a modicum of protection! You may already be infected...

Sent from my SM-N920V using Tapatalk

 

[Nazgulled]

Infected with what?

I'm going to re-enable everything since it didn't fix my original issue.

 

[Nazgulled]

I'm still having loading issues where I need to keep reloading the page and hoping it will work. Sometimes I just need to wait it out and refresh the page again to be able to open it... It happens on the most various sites, not just specific ones. Any thoughts on what might be the problem?

 

[Jerome Des]

Hi !
I've got the exact same problem. It seems to happen on some websites running forum softwares, like flyertalk.com and with some iOS games on my iphone (Clash of clans -> right after the connection to Apple's game center).

Both work perfectly using my cable WAN connection trough the router wifi
They also work fine if I access the web directly over 4G with my phone. So it must be something between the router and 4G usb dongle...

I'm using a Huawei 4G dongle, E3372 and a router ASUS AC66U with 380.57.0. The same problem happen on the latest ASUS stock firmware

I dit set the MTU on the USB parameter in the router to 1492. The value was set based on the optimum settings for my network

 

[Nazgulled]

I'm using a Huawei 4G dongle, E3372 and a router ASUS AC68U with 380.57.0. The same problem happen on the latest ASUS stock firmware.

How are you using that firmware version? How is your dongle connected? Do you use scripts to connect?

 

[Jerome Des]

Sorry, I've got the AC66U, made a mistake in the original post.
I'm not sure to understand what you mean by "how are you using that firmware version" ? As for the dongle connection, it is plugged on the second USB port, with my cable WAN as a fallback connection. I don't use any scripts. The connection is setup manually but trough the GUI, the APN name is specified.

I've spent the last few minutes messing around with the settings and now that I have disabled Dual WAN to leave only USB on, everything looks fine for now, strange....

 

[Jerome Des]

ok, I spoke too fast. Clash of clans is showing the same problem... Damned.

 

[Nazgulled]

It's just that I can't get my dongle to work like you do (with easy setup through the GUI). I need to have custom scripts to make it all work...

 

[Jerome Des]

Which one do you have ? Maybe that is a compatiblity issue on top of the other problem ?

 

[Nazgulled]

I have an E3276s. Yes, it's kinda different but it shouldn't be that different...

 

[sfx2000]

Keeping in mind that most 4G connections are PPP, try dropping the MTU to around 1492 from 1500..