Tunneling IPv6 Through an Absolute IPv4 Network
Problem
You appetite to affix two IPv6 networks through an absolute IPv4 arrangement that doesn't natively abutment IPv6.
Solution
The easiest way to canyon IPv6 cartage through a area of IPv4 arrangement that doesn't action built-in IPv6 abutment is to actualize a simple GRE tunnel:
Router1#configure terminal
Enter agreement commands, one per line. End with CNTL/Z.
Router1(config)#interface Loopback1
Router1(config-if)#ip abode 10.15.1.11 255.255.255.255
Router1(config-if)#exit
Router1(config)#interface Tunnel1
Router1(config-if)#ipv6 abode BBBB:1::1/126
Router1(config-if)#ipv6 rip RIP_PROC enable
Router1(config-if)#tunnel antecedent 10.15.1.11
Router1(config-if)#tunnel destination 172.16.11.9
Router1(config-if)#exit
Router1(config)#end
Router1#
And again you configure the accessory on the added end similarly:
Router9#configure terminal
Enter agreement commands, one per line. End with CNTL/Z.
Router9(config)#interface Loopback1
Router9(config-if)#ip abode 172.16.11.9 255.255.255.255
Router9(config-if)#exit
Router9(config)#interface Tunnel1
Router9(config-if)#ipv6 abode BBBB:1::2/126
Router9(config-if)#ipv6 rip RIP_PROC enable
Router9(config-if)#tunnel antecedent 172.16.11.9
Router9(config-if)#tunnel destination 10.15.1.11
Router9(config-if)#exit
Router9(config)#end
Router9#
Discussion
This archetype is absolutely simpler than a lot of GRE adit agreement examples because the agreement acclimated to abutment the adit end credibility is altered from the agreement that will be casual through the tunnel. As a result, we can advisedly use whatever acquisition agreement we like to administer the acquisition advice about the adit antecedent and destination addresses after annoying about recursive acquisition problems. For added advice on recursive routing, amuse accredit to Chapter 12.
Also, as we acknowledgment in Chapter 12, we acquire advisedly created loopback interfaces to abutment these adit antecedent and destination addresses. This is because we appetite to accomplish abiding that these interfaces never become bare due to a articulation failure. If there is any arrangement aisle to the adit destination, we appetite to accumulate the adit up.
In the example, we acquire configured the adit interfaces to canyon IPv6 acquisition advice application RIP. However, this was aloof for affirmation purposes. You could use whatever agreement is best acceptable for this purpose.
Note that starting in IOS Version 12.3(7)T, Cisco adapted the adit destination command to acquiesce it to acquire an IPv6 address. This makes it accessible to assemble GRE tunnels to backpack IPv4 cartage through an absolute IPv6 arrangement in absolutely the aforementioned way that we acquire tunneled IPv6 cartage through an absolute IPv4 arrangement in this recipe.
See Also