World IPv6 Launch is behind us, but the day accomplished its goal of having major content and access providers enabling IPv6.
Native IPv6 traffic spiking during that day, as did traffic over tunneling protocols such as 6in4 and Teredo.
From the standpoint of increasing IPv6 use, the event was a significant success. But while Launch day may have passed, the security implications of handling IPv6 traffic have not.
Chief among those security issues is that unauthorised tunnels can render IPv6 traffic invisible, creating an unguarded pathway in and out of the corporate network.
Shutting down these pathways requires visibility and understanding of how IPv6 transition mechanisms work.
Understanding why organisations need to migrate to IPv6 is easy. For starters IPv4 is, simply put, running out of space. Each device that connects to the Internet is assigned what is known as an IP address.
The IPv4 protocol allows 32 bits for an IP address, or 232 possible addresses. IPv6 increases that number to 2128. While IPv4 has served the world well, the growing number of devices connecting to the Internet means the protocol's time is running out.
IPv6 has other aspects meant as enhancements over IPv4 as well, including simplifying address assignment.
But there are a number of other implications of turning on IPv6 for network operators. Just like
organisations have a strong focus on protecting the IPv4 side of the network, they must have an equally strong focus on IPv6.
Security practitioners need to learn the basics of the new protocol in order to handle the change.
To help in this regard, best practices have been published on the Web, such as the guidelines from the National Institute of Standards and Technology (NIST).
If security devices support IPv6, now is the time to turn it on. Some operating systems such as Windows Vista and Windows 7 enable IPv6 transition mechanisms by default.
This means these capabilities could be in use without your IT department knowing – ultimately allowing users to bypass firewalls and intrusion prevention systems.
These tunnels work by enabling IPv6 hosts and routers to connect with other IPv6 devices over the IPv4 Internet. The problem with tunnels is that they could cut through your firewall -- enabling attackers to potentially circumvent your security controls and connect to resources inside the network.
For this reason, the use of tunneling protocols like 6to4 to support the transition to IPv6 needs to be carefully considered and most likely should be kept to a minimum.
The fact is, IPv6 may already be running on an organisation's network without their knowledge and could be used as a covert channel by botnets and hackers.
Although an organisation may not actively be running IPv6 on the corporate network, it is important that their security infrastructure is aware of IPv6 traffic.
After all, you can't stop what you can't see.