Automatic IPv6 Tunnel

IPv6-IPv4 Compatible

Adress format : ::A.B.C.D/96

IPv4 Tunnel Source : IPv4 source interface
IPv4 Tunnel Destination : Deducted from the IPv6-Ipv4 compatible addess
IPv6 tunnel interface : Automatically generated from IPv4 Tunnel Source

Configuration

int tunnel 0
tunnel source int lo 0
tunnel mode ipv6ip auto-tunnel

6To4

Adress format : 2002:ipv4-border-router:/48

IPv4 Tunnel Source : IPv4 source interface
IPv4 Tunnel Destination : Deducted from the 6to4 addess
IPv6 tunnel interface : 2002:ipv4-border-router::/48

Configuration

int tunnel 0
tunnel source int lo 0
tunnel mode ipv6ip 6to4
ipv6 address 2002:ipv4-source-address::1/64
ipv6 router 2002::/16 tunnel 0

ISATAP

Adress format : ipv6-global-address:0000:5EFE:ipv4-border-router/128

IPv4 Tunnel Source : IPv4 source interface
IPv4 Tunnel Destination : Deducted from the ipv4 embedded address on ISATAP addess
IPv6 tunnel interface : Generated from the configured ipv6 prefix + ipv4-source-address

Configuration

int tunnel 0
tunnel source int lo 0
tunnel mode ipv6ip isatap
ipv6 address 2001:x:y::/64 eui-64

Manual IPv6 Tunnels

Ipv6 tunnels ares used to interconnect 2 or more IPv6 network through an Ipv4 network.

A sample configuration is :

interface Tunnel 0
no ip address
ipv6 address 2001:CC1E:1:4545::5/64
ipv6 rip RIPng enable
tunnel source Loopback0
tunnel destination 150.1.4.4
tunnel mode ipv6ip | gre
end

Tunnel source and destination should be IPv4 adresses

The differents modes are

GRE : default mode (protocol 47), used tu encapsulate multiple layer 3 protocols
IPV6IP : less overhead than GRE (protocol 41) encapsulate only IPv6