WG1608 + Quectel RM502Q-AE, IPV6 works but no IPV4 address

[kaiyoti]

I have t-mobile 5g sim and I recently tried it my new WG1608 + Quectel RM502Q-AE and after some fiddling around I can get it to connect and register on tmobile network. However, I only get assigned an IPV6 address, IPV4 is assigned as:

Protocol: MBIM Cellular
Address: 255.255.255.255/32
Gateway: 0.0.0.0

I know IPV6 works because I can ping Google's public DNS at 2001:4860:4860::8888, however IPV6 is beyond me and rest of my home network is not on IPV6. I found a couple threads in this forum with others having same issue but it just seemed to have resolved itself for those. I don't have the option to select IPV4 for the APN in the profiles but I see the options in the WAN device that's associated with the device, but it doesn't seem to do anything. I changed it to both "IP" and "IPV4V6" and restart the modem and I still only get IPV6 for both options.

Any help would be appreciated! Thanks.

[gscheb]

Hello,
Might help to know what kind of T-Mobile sim?
Phone, Tablet or home internet Sim?

[kaiyoti]

I'm not entirely sure, it's a mobile citizen unlimited plan through Calyx as far as I know. Is there other way I can tell what kind it is?

[gscheb]

If you look on here see allot of people having various issues with sim swapping on the Calyx plan.

[kaiyoti]

Thanks yah, I have noticed that but most people seem to have issue with connectivity and throttling. I only found two threads about not getting IPV4 and they both just got resolved automatically. I'm going to try a later build of Goldenorb as mine is dated May of 2021 to see if it improves. As I understand some options like setting protocol type in APN is not available.

[Didneywhorl]

You need sept 2021 or newer firmware.

[kaiyoti]

Thanks I tried a 2022 build and I see the option. And choosing the protocol type does make a difference in terms of connection, but if IPV4 is selected, it does not connect. Anything else I can get IPV6 address but no ipv4. I do have this 464-CLAT1 virtual interface in place of IPV4 but still an empty address. LAN IPV6 is not enabled so I suspect that's why I can't access the net. If I ssh into the router, I can ping and connect out likely through the IPV6 wan device. Ping automatically defaults to IPV6 addresses.

This might be a silly question because I have no clue how IPV4 and IPV6 works. Is it possible for a router to take IPV4 lan and redirect to IPV6 WAN and vice versa?

[kaiyoti]

I'm still learning here but I understand the 464XLAT device is meant for allowing IPV4 request over IPV6 connections through some translation service on (I presume on T-Mobile side). The T-Mobile sim in the mifi2000 hotspot device results in an ip address of 192.0.0.2 and gateway of 192.0.0.1 which are private ips. So I'm guessing not getting IPV4 is expected since a lot of articles indicate that T-Mobile services are IPV6 only. So I assume whatever this 464XLAT device is supposed to resolve IPV4 access and that would mean that my router is not configured correctly. But the device for the virtual 464XLAT device doesn't seem to have any configurations available, and disappears when the modem disconnects.

Can someone provide some guidance any further configurations I would need to make for IPV4 to work? Any help is appreciated. Thanks

[Didneywhorl]

The clat interface is requested by the modem when it is given an ipv6 only connection.
You are correct, tmobile is pushing ipv6 only pretty heavily.

So the router needs to support clat (client side) in order to pipe ipv4 requedts through the ipv6 connection. Tmobile has the xlat setup on the server side exit point.

It generally has no "settings" on the router interfaces list and is automatically setup by the router.

Try switching to mbim or qmi and see if it operates differently

[kaiyoti]

Thanks unfortunately QMI wouldn't connect at all.

I'm thinking this is no longer a cellular / modem issue. When I ssh into the router and run "route -n"
I see the CLAT device as the default route. This is likely why I can ping and connect to stuff on the router. (Although opkg update fails). But something is preventing my lan connections to route to this device.

[kaiyoti]

ECM mode seems to work the best as I seem to have full network capabilities like opkg update within the router but still no WAN access for lan.

[Didneywhorl]

Try flashing the WS1208 firmware to the router, using the firmware recovery method. Set that up like you normally would.

[kaiyoti]

Should I be flashing the V2 firmware for ws1208?

[kaiyoti]

I tried the regular wS1208 and getting effectively same result. ECM works the best, but DNS queries on rooter via ssh no longer resolves IPV6. In wg1608 firmware, if I run "ping www.google.com, I get an ipv6 address and successful pings in the WS1208 firmware, that times out and I have to explicitly run ping6. That said any network operations like ssh and opog that relies on DNS all still work. I suspect its DNS incorrectly set up for LAN because it doesn't resolve the same way as router.

[Didneywhorl]

Are you running anything special for the DNS requests?

[kaiyoti]

No, just pings and nslookup.

[kaiyoti]

As it turns out... my wifi connects fine, but my ethernet ports don't.

[Didneywhorl]

Thats def a router firmware issue.

You flashed firmware with the recovery method and then reflashed two more times? Maybe a factory reset in there for good measure?

Have you tested after a reflash without setting up any other settings than system time and APN?

[kaiyoti]

Yah I've been flashing using the recovery method (chinese recovery page with massive button), and each time I'd do a reset for good measure.
What I meant when I said earlier that wifi connects fine but ethernet doesn't... I meant that wifi clients get WAN access, but ethernet LAN clients do not, ethernet clients still get full lan access just no internet, I may have to try other clients but so far I tried a chromebook and a desktop and neither could get internet access. The same clients under wifi could get online. The other thing I did was also manually add a XLAT device so not sure if that made a difference. This very much feels like a config / software routing issue if my ethernet lan devices don't get the same web access but can still get lan access.

BTW. This is under MBIM mode.

That said I'm now facing challenges that many others on the forum is facing with throttling getting about 40mbps but I'm honestly happy I got this far, will keep messing with this to see how much further I can get.

[kaiyoti]

I feel like a monkey jumping and smashing keys but I managed to lock onto n41 band and my network speeds are significantly better now. Still trying to solve the ethernet issue but I did find out (through resetting and retrying) that adding the xlat interface myself did make the wifi work.

[gscheb]

managed to lock onto n41 band and my network speeds are significantly better now.

How far away are you from the tower? Are you using external antennas?

Just noticed today my tower that I am using has just been updated with N41. Haven't got home yet today to look at this. Using outdoor antennas pointed at tower 4.7 Miles away.

[kaiyoti]

I'm 0.67 miles from mine, getting 500mbps average.

[kaiyoti]

After a little more trial and error, I realized that the auto-created CLAT1 device needed to have the "lan" firewall zone. But since the device only appears when the modem connects, and the UI "edit" doesn't allow for setting the firewall zone, I just modified the /etc/config/firewall "lan" zone to also include CLAT1. As soon as I made that change and restarted firewall, I get internet access through everything now.

[Didneywhorl]

Good find! Thanks for reporting

[kaiyoti]

Correction, it doesn't look like applying the zone of 'lan' made the difference. All that was needed was a firewall restart after the modem connects. I now have a start up script that auto reconnects firewall after 5 minutes from boot.

[Didneywhorl]

Correction, it doesn't look like applying the zone of 'lan' made the difference. All that was needed was a firewall restart after the modem connects. I now have a start up script that auto reconnects firewall after 5 minutes from boot.

Share?

[Dairydude]

The easy way to have something happen after the modem has connected is to add the command to /usr/lib/rooter/connect/postconnect.sh.

In this case add, at the end of the file

/etc/init.d/firewall reload

to restart the firewall after the modem connects.

[kaiyoti]

@Didneywhorl yah it's just /etc/init.d/firewall restart in the startup script area,

@Dairydude thanks, that's a better solution!