IPv6 for LTE modem not working

Installing and Using OpenWrt
1

My network config:

config interface 'loopback'
	option device 'lo'
	option proto 'static'
	option ipaddr '127.0.0.1'
	option netmask '255.0.0.0'

config globals 'globals'
	option ula_prefix 'fdcc:509d:268e::/48'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan3'
	list ports 'lan4'
	list ports 'sfp2'

config interface 'lan'
	option device 'br-lan'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'
	option ip6assign '60'

config device
	option name 'br-wan'
	option type 'bridge'
	list ports 'eth1'
	list ports 'wan'

config device
	option name 'eth1'
	option macaddr 'ea:18:59:99:9e:88'

config device
	option name 'wan'
	option macaddr 'ea:18:59:99:9e:88'

config interface 'wan'
	option device 'br-wan'
	option proto 'dhcp'
	option metric '10'

config interface 'wan6'
	option device 'br-wan'
	option proto 'dhcpv6'
	option metric '10'

config interface '4G'
	option proto 'qmi'
	option auth 'none'
	option pdptype 'ipv4v6'
	option device '/dev/cdc-wdm0'

I see an IPv6 address in LUCI

Screenshot from 2023-04-07 08-30-56
Screenshot from 2023-04-07 08-30-56962×254 26.1 KB

But when I run uqmi -d /dev/cdc-wdm0 --get-current-setting, I don't see an IPv6 address?

{
	"pdp-type": "ipv4-or-ipv6",
	"ip-family": "ipv4",
	"mtu": 1500,
	"ipv4": {
		"ip": "10.28.55.83",
		"dns1": "42.105.240.101",
		"dns2": "8.8.8.8",
		"gateway": "10.28.55.84",
		"subnet": "255.255.255.248"
	},
	"ipv6": {
		
	},
	"domain-names": {
		
	}
}

I can successfully ping IPv4 hosts (ping -I wwan0 1.1.1.1) using the wwan0 interface that is created but not IPv6 (ping -I wwan0 ipv6.google.com)

2

You probably need to add option ipv6 '1' to the QMI interface.

3 
config interface '4G'
	option proto 'qmi'
	option auth 'none'
	option pdptype 'ipv4v6'
	option device '/dev/cdc-wdm0'
	option ipv6 '1'

Just tried it out still can't ping ipv6.google.com or any other IPv6 hosts

EDIT: My br-wan has IPv6 and trying with that it works, just form wwan0 interface it doesn't

4

Hello z4e,

I hope all is well with you!

Please how did you solve this issue? I am having the same issue, I am using a ATT SIM.

Thank you!

5

Last I checked, the AT&T wireless network does not run IPV6 at all. It's strictly IPv4 with CGNAT.

6

My modem interface is receiving an ipv6 /128. I believe it supports ipv6 when you get an ipv6 from the carrier. correct? It's the same SIM used for smart devices. Apn broadband

7

Please describe what your issue is and share some details, like ifstatus {lte interface name} and network configuration. No pictures please.