IPv6 is the new version of IP. The most obvious difference from IPv4 is the addresses.

  • IPv4 addresses are 4 bytes, represented in decimal, separated by dots, e.g.
  • IPv6 addresses are 16 bytes, represented in hexadecimal, with each pair of bytes separated by colons, e.g 2001:0db8:85a3:0000:0000:8a2e:0370:7334.

Clearwater can operate over either IPv4 or IPv6, but not both simultaneously (known as “dual-stack”).

This document describes

  • how to configure Clearwater to use IPv6
  • function currently missing on IPv6.


As discussed in the Clearwater installation instructions, there are several ways to install Clearwater, and which way you choose affects how you must configure IPv6.

Manual Install

The process to configure Clearwater for IPv6 is very similar to IPv4. The key difference is to use IPv6 addresses in the /etc/clearwater/local_config file rather than IPv4 addresses when following the manual install instructions.

Note also that you must configure your DNS server to return IPv6 addresses (AAAA records) rather than (or as well as) IPv4 addresses (A records). For more information on this, see the Clearwater DNS usage documentation.

Automated Install

Configuring Clearwater for IPv6 via the automated install process is not yet supported (and Amazon EC2 does not yet support IPv6).

All-in-one Images

Clearwater all-in-one images support IPv6.

Since all-in-one images get their IP configuration via DHCP, the DHCP server must be capable of returning IPv6 addresses. Not all virtualization platforms support this, but we have successfully tested on OpenStack.

Once the all-in-one image determines it has an IPv6 address, it automatically configures itself to use it. Note that since Clearwater does not support dual-stack, all-in-one images default to using their IPv4 address in preference to their IPv6 address if they have both. You should make sure your DHCP server only offers IPv6 addresses to the all-in-one image if you want to use DHCP.

Missing Function

The following function is not yet supported on IPv6.

  • Automated install
  • SIP/WebSockets (WebRTC)