After switching router some apps on Android phone won't load

[Ultrazauberer]

Hello!

I'm using a new C2600 with OpenWRT 18.06.2 and since then my eBay and AliExpress app stopped working on my smartphone.
I already resetted the apps but nothing changed. I can browse normally on the eBay website.

The app looks like this:

I got a hint that maybe IPv6 can cause this problem:

Before I switched to OpenWRT I could normally use the apps. Also when I'm not connected to my home wifi it's working too.

Also on my desktop some websites are loading for 2-3 seconds and than they are instant there. It all feels a little bit laggy.

Could this be a firewall issue or an IPv6 problem?

Any suggestions for troubleshooting are welcome!

Thanks!

[slh]

ifdown wan6 might already be enough to tell you.

[Pilot6]

It is quite a common problem when ISP has a broken IPv6.
Your old router probably didn't support IPv6, and you had no problems.

The easiest way to "fix" this is to disable IPv6 in Openwrt. But it is better to find out what is the real problem.

[Ultrazauberer]

Unfortunaly shutting down 'wan6' doesn't change anything. Before I executed the command there wasn't even a 'wan6' interface listed after doing a ifconfig:

root@OpenWrt:~# ifconfig
br-lan    Link encap:Ethernet  HWaddr A4:2B:B0:DA:1B:AC
          inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::a62b:b0ff:feda:1bac/64 Scope:Link
          inet6 addr: fd69:8650:d5ca::1/60 Scope:Global
          inet6 addr: 2003:cd:7f34:1500::1/60 Scope:Global
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:11533009 errors:0 dropped:0 overruns:0 frame:0
          TX packets:60647594 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:935225193 (891.8 MiB)  TX bytes:85670184959 (79.7 GiB)

eth0      Link encap:Ethernet  HWaddr A4:2B:B0:DA:1B:AD
          inet6 addr: fe80::a62b:b0ff:feda:1bad/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:62907224 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11354737 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:3606541360 (3.3 GiB)  TX bytes:1112072125 (1.0 GiB)
          Interrupt:30

eth0.7    Link encap:Ethernet  HWaddr A4:2B:B0:DA:1B:AD
          inet6 addr: fe80::a62b:b0ff:feda:1bad/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:62907224 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11354730 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:88373557248 (82.3 GiB)  TX bytes:1066652379 (1017.2 MiB)

eth1      Link encap:Ethernet  HWaddr A4:2B:B0:DA:1B:AC
          inet6 addr: fe80::a62b:b0ff:feda:1bac/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:11229579 errors:0 dropped:0 overruns:0 frame:0
          TX packets:60127880 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1056927860 (1007.9 MiB)  TX bytes:3862186557 (3.5 GiB)
          Interrupt:31

eth1.1    Link encap:Ethernet  HWaddr A4:2B:B0:DA:1B:AC
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:11125381 errors:0 dropped:0 overruns:0 frame:0
          TX packets:60127868 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:848284534 (808.9 MiB)  TX bytes:85226051917 (79.3 GiB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:8903 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8903 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:797032 (778.3 KiB)  TX bytes:797032 (778.3 KiB)

pppoe-wan Link encap:Point-to-Point Protocol
          inet addr:46.89.134.214  P-t-P:62.155.240.37  Mask:255.255.255.255
          inet6 addr: fe80::1c0c:dee5:1ee1:59ca/10 Scope:Link
          inet6 addr: 2003:cd:7fff:33d7:1c0c:dee5:1ee1:59ca/64 Scope:Global
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1492  Metric:1
          RX packets:62841033 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11287435 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:87868046970 (81.8 GiB)  TX bytes:816152481 (778.3 MiB)

wlan0     Link encap:Ethernet  HWaddr A4:2B:B0:DA:1B:AB
          inet6 addr: fe80::a62b:b0ff:feda:1bab/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:186236 errors:0 dropped:0 overruns:0 frame:0
          TX packets:35071990 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:45032718 (42.9 MiB)  TX bytes:48067963422 (44.7 GiB)

wlan1     Link encap:Ethernet  HWaddr A4:2B:B0:DA:1B:AC
          inet6 addr: fe80::a62b:b0ff:feda:1bac/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:234527 errors:0 dropped:0 overruns:0 frame:0
          TX packets:35130104 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:49287858 (47.0 MiB)  TX bytes:48211474111 (44.9 GiB)

But there is an interface in the /etc/config/network named wan6:

config interface 'wan6'
        option ifname 'eth0.7'
        option proto 'dhcpv6'

In Luci I can see a dynamic IPv6 interface which I couldn't stop/edit/delete:

If I do again the IPv6 test on the smartphone again it shows IPv6 connectivity.

@Pilot6
Yeah, it would be much more satisfying if full IPv6 would work. Do you have any clue where the problem is?

[Pilot6]

Your IPv6 is coming not from WAN6, but from WAN, where pppoe-wan is configured to use Ipv6 as well. Virtual WAN_6 is configured. You can disable IPv6 in WAN properties.

[Ultrazauberer]

You are right. I disabled IPv6 and it worked.

Too bad it didn't solve the loading issue of the eBay app which drives me crazy. I have the feeling the problem wasn't IPv6.

What makes me wonder: the eBay app is loading on the smartphone of my wife. That should than normally a problem of my smartphone but why this only happens when I'm connected to my home wifi and not when I'm connected to my corporate wifi or on the 4g network?

[mk24]

When your network is v4 only, turn off the DHCPv6 server on the LAN which is enabled by default.

[Ultrazauberer]

I tried it and now it looks like this:

Still no improvement and also the Amazon Alexa app isn't working and I have an endless loading screen.

I wonder if I should install OpenWRT on a different router and test it again?

[slh]

The ISP in question here (Deutsche Telekom AG/ T-Online) has a functioning IPv6 deployment, sadly dynamic IPv6 prefixes, but without nasty surprises.

[Ultrazauberer]

I'm currently preparing a Netgear EX6150v2 as a router and I will test it with this device. Maybe then it's working. If not, then it has to be my smartphone or the combination of the installed OpenWRT firmware and my client.

[Ultrazauberer]

Okay, thanks to the great help of the forum I could use my Netgear EX6150v2 as a router. Unfortunaly it doesn't change the behavior of my smartphone. Some apps won't load and some of them feel laggy (messages in telegram are very delayed).

I switched to a third router: A Linksys EA8300 with stock firmware. This time I have more luck and my smartphone works as intended. That's pretty strange! I also performed a IPv6 test and on all devices I have full IPv6 connectivity.

Than I thought maybe the wlan drivers (all ath10k) are not working in the combination with my smartphone. But I'm using a second access point upstairs for better wifi coverage. It's a TP-Link WDR4300 with stock firmware and when my smartphone is connected there, it doesn't change anything. This means if the main router working fully for my smartphone than also the AP is working fine. If the main router not behave as intended than also the AP won't.

This leads me to the conclusion that the wifi part is not the problem and it has to do with my wired lan traffic (or routing or firewalling). Maybe someone has the right idea? Tomorrow I will test a really old Netgear WNDR3800 with OpenWRT (version 12.xx?) and look what happens.

[Ultrazauberer]

Ok, now I have the old WNDR3800 with OpenWrt Attitude Adjustment r33624 / LuCI Trunk (trunk+svn9348) running. I know, it's a totally outdated version, but I just want to try it. I have no IPv6 Support and I still can't use my eBay or Amazon Alexa app on my smartphone.
Now it's the question what does OpenWRT different in comparison with all other routers with factory firmware? Is there a good way to sniff the packets from my android phone while try to start the non loading apps and then the same case with a working router?

I have the feeling that something like UPnP in these consumer devices are open all ports in the firewall or something.

[Ultrazauberer]

I found the solution here in the forum after googling more specific.

Upgraded to android pie: netflix and amazon stopped working on OpenWrt's wifi

I did found the solution: MSS clamping was missing a tick in the firewall tab. [Schermata%20del%202018-11-16%2018-06-58] Now both apps work fine.

It was the firewall missing the setting: MSS clamping. Now everything works fine!

[slh]

hmm, isn't that default for wan? At least I can't remember ever having enabled it (but it is, at least for my PPPoE/ VDSL connection - but I may have cargo culted it from years ago).

--
great to read you you got your issue sorted, as it looked pretty weird.

[Ultrazauberer]

Sadly it's not on per default. I tried 3 routers (2 fresh installed with the latest 18.06.4 stable) and non of them were working because it wasn't on.