IPv6

Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP) which was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion. IPv6 is intended to replace IPv4. IPv6 uses a 128-bit address, theoretically allowing 2128, or approximately 3.4×1038 addresses. The actual number is slightly smaller, as multiple ranges are reserved for special use or completely excluded from use. The total number of possible IPv6 address is more than 7.9×1028 times as many as IPv4, which uses 32-bit addresses and provides approximately 4.3 billion addresses. The two protocols are not designed to be interoperable, complicating the transition to IPv6. However, several IPv6 transition mechanisms have been devised to permit communication between IPv4 and IPv6 hosts.
Introduction This tutorial is a HowTo for setting up IPv6 NAT on an OpenWRT router. The information on the environment is listed below. Network Environment: China Education and Research Network Center with dual-stack IPv6 Network Device: NETGEAR R6100 (128M RAM) Firmware Version: OpenWrt Chaos Calmer 15.05 Install Dependencies for OpenWRT Login to the OpenWRT router via SSH and run the following commands: opkg update opkg install ip6tables opkg install kmod-ipt-nat6 opkg install iputils-tracepath6 Setup IPv6 for Local-area Network Edit /etc/config/network, and add the following lines in config interface 'lan':