Fix IPv6 on servers from before November 2024

This guide is for cloud servers ordered before 22 November 2024. Those servers sometimes pick up extra, automatic IPv6 addresses next to the one we assigned, and IPv6 then doesn't work properly.

Ordered your server later? Then this guide isn't for you. Your server gets its own IPv6 /64 from the dashboard, see Turn on IPv6 for your cloud server.

In the commands below, replace:

• INTERFACE with your network interface, for example eth0 (see ip a)
• YOUR_IPV6/64 with the IPv6 address we assigned to your server
• AUTO_IPV6/64 with an automatic address you want to remove

1. Add your own IPv6 address

If it isn't on the server yet:

sudo ip -6 addr add YOUR_IPV6/64 dev INTERFACE

2. Remove the automatic addresses

List the addresses with ip -6 addr show dev INTERFACE, then remove every global address that isn't yours:

sudo ip -6 addr del AUTO_IPV6/64 dev INTERFACE

3. Stop new automatic addresses

sudo sysctl -w net.ipv6.conf.INTERFACE.autoconf=0
sudo sysctl -w net.ipv6.conf.INTERFACE.accept_ra=0

4. Keep it after a restart

Add these two lines to the end of /etc/sysctl.conf:

net.ipv6.conf.INTERFACE.autoconf = 0
net.ipv6.conf.INTERFACE.accept_ra = 0

Then load them with sudo sysctl -p. Also make sure your own IPv6 address is in your network configuration (netplan or /etc/network/interfaces), so it comes back after a restart.

Want your own /64?

Newer servers get a whole IPv6 subnet of their own. We can move an older server to that setup too. Open a ticket under Support, mention your server's name, and we'll arrange it with you.

Still no IPv6? Open a ticket under Support and we'll help.