Knowledgebase

Introduction

Rcs supports IPv6 for all VPS and Bare Metal instances. If you select Enable IPv6 in the Additional Features section when you deploy a new instance, you do not need to configure anything because all network configuration on a new instance is handled by cloud-init.

However, if you add IPv6 to a existing instance, use this guide to configure the new network address.

How to add IPv6 to an Instance

1. IPv6 autoconfiguration depends on ICMP protocol. Please verify you haven't blocked ICMP in the OS firewall.

2. Navigate to the Settings tab for the instance.

3. Select the IPv6 menu.

4. Click the Assign IPv6 Network button.

   

5. Restart the server via the Rcs Customer Portal. Important: rebooting via SSH doesn't activate the new network.

Examples

Rcs provides Configuration Examples on the IPv6 Settings menu. Please follow that link to see pre-configured configuration examples for your VPS instance.

IPv6 on CentOS

CentOS 8

Dynamic configuration

Populate /etc/sysconfig/network-scripts/ifcfg-ens3 with:

TYPE="Ethernet"
DEVICE="ens3"
ONBOOT="yes"
BOOTPROTO="dhcp"
IPV6INIT="yes"
IPV6_AUTOCONF="yes"
IPV6ADDR_SECONDARIES="2001:db8:1000::100 2001:db8:1000::200"

• The primary IPv6 is dynamic.
• 2001:db8:1000::200 is the optional static secondary IPv6. Remove the IPV6ADDR_SECONDARIES line if a secondary address isn't required, or replace the example with an address in your IPv6 subnet.

Restart the connection, or reboot.

nmcli con load /etc/sysconfig/network-scripts/ifcfg-ens3
nmcli con up 'System ens3'

CentOS 6 through 7

Add the following lines to /etc/sysconfig/network-scripts/ifcfg-eth0.

IPV6INIT="yes"
IPV6ADDR="2001:db8:1000::100/64"
IPV6_AUTOCONF="yes"
IPV6ADDR_SECONDARIES="2001:db8:1000::200/64"

• 2001:db8:1000::100 is the primary IPv6, replace the example with an address in your IPv6 subnet.
• 2001:db8:1000::200 is the optional secondary IPv6. Remove the IPV6ADDR_SECONDARIES line if a secondary address isn't required, or replace the example with an address in your IPv6 subnet.

Restart networking or reboot.

service network restart

IP forwarding

If you have IP forwarding enabled, such as when using your server as a VPN, add the following lines to /etc/sysctl.conf:

net.ipv6.conf.all.accept_ra=2
net.ipv6.conf.eth0.accept_ra=2

These variables default value is 1, which prevents IPv6 from working. To verify the status of IP forwarding, run:

# sysctl net.ipv4.ip_forward

IPv6 on Debian

Debian 9 and later

Dynamic configuration

For dynamic configuration, add the following lines to /etc/network/interfaces.

iface ens3 inet6 auto

Restart networking or reboot.

systemctl restart networking.service

Static configuration

For static configuration, add the following lines to /etc/network/interfaces.

iface ens3 inet6 static
address 2001:db8:1000::100
netmask 64
up /sbin/ip -6 addr add dev ens3 2001:db8:1000::200

• 2001:db8:1000::100 is the primary IPv6, replace the example with an address in your IPv6 subnet.
• 2001:db8:1000::200 is the optional secondary IPv6. Remove the example IP address line if a secondary address isn't required, or replace the example with an address in your IPv6 subnet.

Restart networking or reboot.

systemctl restart networking.service

Debian 8

Dynamic configuration

For dynamic configuration, add the following lines to /etc/network/interfaces.

iface eth0 inet6 auto

Restart networking or reboot.

systemctl restart networking.service

Static configuration

For static configuration, add the following lines to /etc/network/interfaces.

iface eth0 inet6 static
address 2001:db8:1000::100
netmask 64
up /sbin/ip -6 addr add dev eth0 2001:db8:1000::200

• 2001:db8:1000::100 is the primary IPv6, replace the example with an address in your IPv6 subnet.
• 2001:db8:1000::200 is the optional secondary IPv6. Remove the example IP address line if a secondary address isn't required, or replace the example with an address in your IPv6 subnet.

Restart networking or reboot.

systemctl restart networking.service

IPv6 on Fedora

Fedora 29 through 32

Add the following lines to /etc/sysconfig/network-scripts/ifcfg-ens3.

    nmcli con mod 'Wired connection 1' ipv6.method 'auto' ipv6.addresses ''
    nmcli con mod 'Wired connection 1' +ipv6.addresses '2001:db8:1000::200/128'
    nmcli con up 'Wired connection 1'

• The primary IPv6 is dynamic.
• 2001:db8:1000::200 is the optional static secondary IPv6. Remove that line if a secondary address isn't required, or replace the example with an address in your IPv6 subnet. Additional addresses can be added in the same fashion.

Restart networking or reboot.

systemctl restart network.service

Fedora 26 through 28

Add the following lines to /etc/sysconfig/network-scripts/ifcfg-ens3.

    IPV6INIT="yes"
    IPV6ADDR="2001:db8:1000::100/64"
    IPV6_AUTOCONF="yes"
    IPV6ADDR_SECONDARIES="2001:db8:1000::200/64"

• 2001:db8:1000::100 is the primary IPv6, replace the example with an address in your IPv6 subnet.
• 2001:db8:1000::200 is the optional secondary IPv6. Remove the IPV6ADDR_SECONDARIES line if a secondary address isn't required, or replace the example with an address in your IPv6 subnet.

Restart networking or reboot.

systemctl restart network.service

IPv6 on FreeBSD

This applies to FreeBSD version 10 through 13.

Dynamic configuration

Add the following lines to the /etc/rc.conf file.

ifconfig_vtnet0_ipv6="inet6 accept_rtadv"
ipv6_activate_all_interfaces="YES"
rtsold_enable="YES"
rtsold_flags="-aF"

Static configuration

Add the following lines to the /etc/rc.conf file. Replace the example with an address in your IPv6 subnet.

rtsold_enable="YES"
ipv6_activate_all_interfaces="YES"
rtsold_flags="-aF"
ifconfig_vtnet0_ipv6="inet6 2001:db8:1000::100 prefixlen 64"

Start the router solicitation daemon or reboot.

service rtsold start

Add Second IPv6 to an Instance

Optionally, you may configure a secondary IPv6 address for your instance.

1. Add the following line to /etc/rc.conf. Replace the example with an address in your IPv6 subnet.

    ifconfig_vtnet0_alias0="inet6 2001:db8:1000::200 prefixlen 64"

2. Start the router solicitation daemon or reboot.

    # service rtsold start

IPv6 on OpenBSD

Requirements

• Please ensure that slaacd is enabled and running.

• IPv6 autoconfiguration depends on ICMP protocol. Please verify you haven't blocked ICMP routeradv, neighbrsol, neighbradv packet types. For example, this ruleset for pf.conf passes the required traffic:

    pass in on egress inet6 proto icmp6 all icmp6-type { echoreq routeradv neighbrsol neighbradv }

Procedure

1. Add the following line to /etc/hostname.vio0.

   • If using OpenBSD 6.0 through 6.2:

       inet6 autoconf -autoconfprivacy

   • If using OpenBSD 6.3 through 6.8:

       inet6 autoconf -autoconfprivacy -soii

   • If using OpenBSD 6.9 or later:

       inet6 autoconf -soii -temporary

2. Restart the interface or reboot.

    # sh /etc/netstart vio0

3. Verify the interface status with slaacctl.

    # slaacctl show interface

Add Second IPv6 to an Instance

Optionally, you may configure a secondary IPv6 address for your instance.

1. Add the following line to /etc/hostname.vio0. Replace the example with an address in your IPv6 subnet.

    inet6 alias 2001:db8:1000::200 64

2. Restart the interface or reboot.

    # sh /etc/netstart vio0

3. Verify the interface status with slaacctl.

    # slaacctl show interface

IPv6 on Ubuntu

This guide applies to Ubuntu 14.04 and later.

Ubuntu 17.10 and later

Populate the /etc/netplan/10-ens3.yaml file with the following text.

network:
  version: 2
  renderer: networkd
  ethernets:
    ens3:
      dhcp4: yes
      addresses:
        - '2001:db8:1000::200/64'

• The primary IPv6 is dynamic.
• 2001:db8:1000::200 is the optional static secondary IPv6. Remove addresses: and the example IPv6 if a secondary address isn't required, or replace the example with an address in your IPv6 subnet.

Update networking or reboot.

netplan apply

Ubuntu 16.04 through 17.04

Dynamic configuration

For dynamic configuration, add the following lines to the /etc/network/interfaces file.

iface ens3 inet6 auto

Restart networking or reboot.

systemctl restart networking.service

Static configuration

For static configuration, add the following lines to the /etc/network/interfaces file.

iface ens3 inet6 static
address 2001:db8:1000::100
netmask 64
up /sbin/ip -6 addr add dev ens3 2001:db8:1000::200

• 2001:db8:1000::100 is the primary IPv6, replace the example with an address in your IPv6 subnet.
• 2001:db8:1000::200 is the optional secondary IPv6. Remove the example IP address line if a secondary address isn't required, or replace the example with an address in your IPv6 subnet.

Restart networking or reboot.

systemctl restart networking.service

Ubuntu 14.04

Dynamic configuration

For dynamic configuration, add the following lines to the /etc/network/interfaces file.

iface eth0 inet6 auto

Reboot the instance.

Static configuration

For static configuration, add the following lines to the /etc/network/interfaces file.

iface eth0 inet6 static
address 2001:db8:1000::100
netmask 64
up /sbin/ip -6 addr add dev eth0 2001:db8:1000::200

• 2001:db8:1000::100 is the primary IPv6, replace the example with an address in your IPv6 subnet.
• 2001:db8:1000::200 is the optional secondary IPv6. Remove the example IP address line if a secondary address isn't required, or replace the example with an address in your IPv6 subnet.

Reboot the instance.

IP forwarding

If you have IP forwarding enabled, such as when using your server as a VPN, add the following lines to /etc/sysctl.conf:

net.ipv6.conf.all.accept_ra=2
net.ipv6.conf.eth0.accept_ra=2

These variables default value is 1, which prevents IPv6 from working. To verify the status of IP forwarding, run:

# sysctl net.ipv4.ip_forward

IPv6 on Windows Server

This applies to Windows Server 2012 R2 and later.

1. Find the public interface name on your system. You can use ipconfig /all or navigate the Windows Control Panel.

2. Run the following commands.

   • Replace Ethernet with your public interface name, and replace the example addresses with an address in your IPv6 subnet. You can skip the second address if you don't have one.

       netsh interface ipv6 set global randomizeidentifiers=disabled
       netsh interface ipv6 add address interface="Ethernet" address="2001:db8:1000::100/64"
       netsh interface ipv6 add address interface="Ethernet" address="2001:db8:1000::200/64"