Router has IPV6 connectivity but connected devices doesn't

In my area, there's no wired connection available, so I have been using the internet via hotspot from a cheap 4G mobile. But I was facing some issues with this, first, the range was very limited and second, the phone supports only WiFi 4 - 2.4G, 20Mhz, and NSS 1.

I got a maximum of 45Mbps Download & 35Mbps Upload speed when using its hotspot. But when using the phone in USB Tethering mode, I got up to 90 Mbps Download & 40+Mbps Upload speed.

So I purchased a TP-Link C6U Router which has a USB port and installed OpenWrt in it. I installed the USB Tethering RNDIS Package in it, and now I can connect the phone with the router and get 80+ Mbps speed via WiFi and a better range as well.

opkg update
opkg install kmod-usb-net-rndis

NOW THE ISSUE I'M FACING:

The router gets IPv6 & I can ping to IPv6 sites using SSH from 192.168.1.1 but my mobiles and laptops don't get IPV6 addresses and can't open or ping ipv6 addresses.

While on my MacBook:

I have made no changes to OpenWrt yet, only installed the RNDIS package & created uwan & uwan6 interfaces and linked to USB0.

What should I do to fix this issue? I do get IPv6 when I directly connect to my phone hotspot.

You do not have a /64 prefix on your uwan6 interface

it shows /64 & /128 both & router can ping to ipv6 from ssh. :thinking: any workaround?

Use ipv6 relay mode
https://openwrt.org/docs/guide-user/network/ipv6/configuration#ipv6_relay

I did my config as it is but via Luci

cat /etc/config/dhcp
config dhcp lan
    option dhcpv6 relay
    option ra relay
    option ndp relay
    ...
 
config dhcp wan6
    option dhcpv6 relay
    option ra relay
    option ndp relay
    option master 1
    option interface wan6

Now on my Android phone, I'm seeing ipv6 as per ipv6-test.com but on my MacBook result on the site is still the same and I can't ping ipv6 sites

but now it shows some IPV6 addresses in network settings

and when I ping from terminal

Can u please check my above reply and revert?

So I added the IPV6 address as DNS and now I have IPV6 connectivity on Mac as well but it's unstable. I did ping6 google.com in the terminal and after a few seconds when I checked, I saw 20-50% packet loss.

160 packets transmitted, 125 packets received, 21.9% packet loss

and after a few mins, I lose IPV6 connectivity completely.

--- google.com ping6 statistics ---
37 packets transmitted, 0 packets received, 100.0% packet loss

Does anyone have a solution? :sweat_smile:

Try to add the following option in addition to the options you have under config dhcp ‘lan’

        option ndproxy_slave ‘1’