Automatic 6to4 Tunel IPv6 Tunel (IV)

Uno de los mecanismos de transición entre IPv4 e IPv6 es el tunel Automatic 6 to 4, nos permite utilizar direccionamiento IPv6 sobre enlaces IPv4.

Estableceremos un tunel automático (sin poner ips destino) entre dos sedes que solo se comunican por IPv4.
Usaremos el ejemplo:





Se suele usar el rango 2002::/16
2002:IP:V4::x

R1
19.19.12.1 podria ser

19 = 13 Hex
12 = 0C Hex
01 = 01 HEX
2002:1313:0C01::1/64


19 = 13 Hex
45 = 2D Hex
05 = 05 HEX
2002:1313:2D05::5/64


R1#sh run int tun 0
Building configuration...

Current configuration : 151 bytes
!
interface Tunnel0
 no ip address
 ipv6 address 2002:1313:0C01::1/64
 tunnel source 19.19.12.1
 tunnel mode ipv6ip 6to4
end

R5#sh run int tun 0
Building configuration...

Current configuration : 151 bytes
!
interface Tunnel0
 no ip address
 ipv6 address 2002:1313:2D05::5/64
 tunnel source 19.19.45.5
 tunnel mode ipv6ip 6to4
end

Verificamos
R5#sh int tun0
Tunnel0 is up, line protocol is up
  Hardware is Tunnel
  MTU 1514 bytes, BW 9 Kbit/sec, DLY 500000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation TUNNEL, loopback not set
  Keepalive not set
  Tunnel source 19.19.45.5, destination UNKNOWN
  Tunnel protocol/transport IPv6 6to4


Necesitamos obligatoriamente enrutamiento estatico

R1(config)#ipv6 route 2002::/16 tun 0
R5(config)#ipv6 route 2002::/16 tun 0

o bien
R1(config)#ipv route ::/0 tun0
R5(config)#ipv route ::/0 tun0


R5#ping 2002:1313:0C01::1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2002:1313:C01::1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 76/96/112 ms