24-1
v1.0, June 2010
Chapter
24
Tunnel
There are two methods for Pv6 sites to communicate with each other over the IPv4 network. 6in4 tunnel and
6to4 tunnel. The 6in4 tunnel encapsulate IPv6 traffic over explicitly-configuredIPv4 destination or endport
of the tunnel with IP protocol number setting to 41. The 6to4 tunnel IPv6 prefix is constructed by
prepending 2002(hex) to the global IPv4 address. for example, if IPv4 address is 4.4.4.1, the tunnel IPv6
prefix would be 2002:404:401::/16..
The 6to4 tunnels are automatically formed IPv4 tunnels carrying IPv6 traffic. The automatic tunnel’s IPv4
destination address is derived from the 6to4 IPv6 address of the tunnel’s nexthop. It supports the
functionality of a 6to4 border router that connects a 6to4 site to a 6to4 domain. It sends/receives tunneled
traffic from routers in a 6to4 domain that includes other 6to4 border routers and 6to4 relay routers. The
example creates a 6in4 tunnel between GSM7328S_1 and GSM7328S_2. The tunnel carries IPv6 packets
over IPv4 packets.
IPv4 Network
GSM7328S_1
GSM7328S_2
1/0/1
1/0/13
Figure
24-1
CLI: Creating a Tunnel
(Netgear Switch) #config
(Netgear Switch) (Config)#ip routing
(Netgear Switch) (Config)#ipv6 forwarding
(Netgear Switch) (Config)#ipv6 unicast-routing
(Netgear Switch) (Config)#interface 1/0/1
(Netgear Switch) (Interface 1/0/1)#routing
(Netgear Switch) (Interface 1/0/1)#ip address 192.168.1.1 255.255.255.0
(Netgear Switch) (Interface 1/0/1)#exit
On GSM7328S_1