This tunnel configuration example provides the CLI input for both Router 1 and Router 2 as displayed in Tunnel Configuration Example:
System(su)->configure System(su-config)->interface loopback 1 System(su-config-intf-loop.0.1)->ip address 88.88.88.1 255.255.255.255 primary System(su-config-intf-loop.0.1)->no shutdown System(su-config-intf-loop.0.1)->exit System(su-config)->interface tunnel 1 System(su-config-tun.0.1)->tunnel mode gre System(su-config-tun.0.1)->tunnel source 88.88.88.1 System(su-config-tun.0.1)->tunnel destination 99.99.99.1 System(su-config-tun.0.1)->ipv6 address 2111::10/64 System(su-config-tun.0.1)->tunnel probe 99.99.99.1 probe-name default System(su-config-tun.0.1)->tunnel keyword 123456 System(su-config-tun.0.1)->no shutdown System(su-config-tun.0.1)->exit System(su-config)->ip route 99.99.99.1/32 vlan 50 System(su-config)->ipv6 route 2333::0/64 interface tun.0.1
System(su)->configure System(su-config)->interface loopback 1 System(su-config-intf-loop.0.1)->ip address 99.99.99.1 255.255.255.255 primary System(su-config-intf-loop.0.1)->no shutdown System(su-config-intf-loop.0.1)->exit System(su-config)->interface tunnel 1 System(su-config-tun.0.1)->tunnel mode gre System(su-config-tun.0.1)->tunnel source 99.99.99.1 System(su-config-tun.0.1)->tunnel destination 88.88.88.1 System(su-config-tun.0.1)->ipv6 address 2111::10 System(su-config-tun.0.1)->tunnel probe 88.88.88.1 probe-name default System(su-config-tun.0.1)->tunnel keyword 123456 System(su-config-tun.0.1)->no shutdown System(su-config-tun.0.1)->exit System(su-config)->ip route 88.88.88.1/32 vlan 50 System(su-config)->ipv6 route 2111::0/64 interface tun.0.1