How do I completely disable IPv6 on my router?

I'm having some issues on many devices on my network, that might be IPv6 related. In order to troubleshoot it, I want to entirely disable IPv6 on the router itself.

I'm using a Technicolor TD5130v2 as modem/router/ap. Its manual doesn't seem to cover IPv6 except for a brief mention on "Supports IPv4 and IPv6 protocols" on the features page. The interface screenshots on the manual differ from the actual interface on my router, despite it visually being the same; I suspect it uses a custom firmware for my ISP. This suspicion is even stronger because (1) when installed, it enabled a hidden SSID called " WiFi", (2) it says "_FW_v17" on the start page, (3) I can browse to . I have tried to apply the latest firmware available, but the router rejects it with a "wrong file format" message.

I have tried to find the IPv6 settings and disable it anyway. On the admin interface, however, when I perform a "ping to the all routers link-local address", I still get a response from my router.

Here's the output of ip -6 addr and ip -6 route:

ubuntu@ubuntu:~$ ip -6 addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 inet6 ::1/128 scope host valid_lft forever preferred_lft forever
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000 inet6 fe80::3e77:e6ff:XXXX:XXXX/64 scope link valid_lft forever preferred_lft forever
ubuntu@ubuntu:~$ ip -6 route
fe80::/64 dev wlan0 proto kernel metric 256
default dev wlan0 proto kernel metric 256 expires 86333sec
default via fe80::9e97:26ff:XXXX:XXXX dev wlan0 proto ra metric 1024 expires 233sec

I have disabled every "IPv6" setting I could find (see pictures below):

2 Answers

Desactivation should be done on ubuntu also.

have you tried editing /etc/sysctl.conf with .. ?

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

or follow instruction from Same question on Ubuntu forum ?

And of course, same to be done on android device.

To start off, you need to login to the router via Telnet. This is easily accomplished on a Linux based system with the telnet command:

telnet 192.168.1.254

(replace this address with your router's address if it is incorrect, you may need to install telnet via your Linux system's package manager)

Then, simply run the following commands to disable ipv6:

:ppp ifdetach intf Internet
:ppp ifconfig ipv6 disabled intf Internet
:ppp attach intf Internet

This is basically a reverse of the method described here. I can't test this because I do not have a router of the same type.