How to Configure IPv6 on Your Breeze

How to Configure IPv6 on Your Breeze

IPv6 adoption continues to grow, and configuring it on your Breeze instance ensures future-proof connectivity and access to the expanding IPv6 internet. This guide walks you through enabling and configuring IPv6 on both Debian/Ubuntu and CentOS/RHEL-based systems.

Checking Current IPv6 Status

First, verify whether IPv6 is already enabled on your Breeze:

ip -6 addr show
sysctl net.ipv6.conf.all.disable_ipv6

If the sysctl value returns 1, IPv6 is disabled at the kernel level. A value of 0 means it is enabled.

Enabling IPv6 in sysctl

If IPv6 is disabled, enable it by editing /etc/sysctl.conf:

net.ipv6.conf.all.disable_ipv6 = 0
net.ipv6.conf.default.disable_ipv6 = 0
net.ipv6.conf.lo.disable_ipv6 = 0

Apply the changes immediately:

sudo sysctl -p

Static IPv6 Configuration on Ubuntu/Debian (Netplan)

Edit the Netplan configuration file, typically located at /etc/netplan/01-netcfg.yaml:

network:
  version: 2
  ethernets:
    eth0:
      addresses:
        - 203.0.113.10/24
        - "2001:db8::10/64"
      routes:
        - to: default
          via: 203.0.113.1
        - to: "::/0"
          via: "2001:db8::1"
      nameservers:
        addresses:
          - 8.8.8.8
          - "2001:4860:4860::8888"

Apply with sudo netplan apply.

Static IPv6 on CentOS/RHEL (NetworkManager)

Use nmcli to add an IPv6 address:

sudo nmcli con mod eth0 ipv6.addresses "2001:db8::10/64"
sudo nmcli con mod eth0 ipv6.gateway "2001:db8::1"
sudo nmcli con mod eth0 ipv6.dns "2001:4860:4860::8888"
sudo nmcli con mod eth0 ipv6.method manual
sudo nmcli con up eth0

Testing IPv6 Connectivity

Verify your configuration with these commands:

ping6 -c 4 ipv6.google.com
ip -6 route show
curl -6 https://ifconfig.co

Firewall Considerations

Remember that IPv6 has its own firewall rules. If you use iptables, you need ip6tables for IPv6 traffic. With firewalld, IPv6 rules are managed automatically. Ensure you allow ICMPv6 traffic, as it is essential for IPv6 neighbor discovery and path MTU detection:

sudo ip6tables -A INPUT -p icmpv6 -j ACCEPT
sudo ip6tables -A OUTPUT -p icmpv6 -j ACCEPT

Dual-Stack Best Practices

Running dual-stack (IPv4 and IPv6 simultaneously) is the recommended approach. Ensure your applications bind to both address families, your DNS has both A and AAAA records, and your monitoring covers both protocols. Most modern services handle dual-stack transparently, but always test both paths after configuration changes on your Breeze.