IPv6 Training (Cisco) Using the “tunnel source” Command
The “tunnel source” Command
By Charles Ross CCNP #CSCO10444244
The most obvious reason why you’re in the process of reading this article is because you’re curious on how to create a “tunnel” between two Cisco routers. Well, if that’s the case you’re headed in the right direction.
In this article, I’m going to define the Cisco IOS interface configuration command named “tunnel source” and also explain its usage.
So, on that note; let’s begin. The first thing I need to tell you is that in order to use the “tunnel source” command within an IPv6 network environment; your Cisco routers need to be running Cisco IOS 12.3(7)T or higher.
Network administrators (like you) use the “tunnel source” interface configuration command, to set the source address for a tunnel interface.
Below is the proper syntax and example of using the command:
Syntax: tunnel source {ip-address | ipv6-address | interface-type interface-number}
ip-address -- Is the argument that represents the IPv4 address used as the source address for packets in the tunnel.
ipv6-address -- Is the argument that represents the IPv6 address used as the source address for packets in the tunnel.
interface-type -- Is the argument that represents the Interface type (example: fastethernet)
interface-number -- Is the argument that represents the port, connector, or interface card number.
Example:
router>enable
router#configure terminal
router(config)#interface tunnel 0
router(config-if)#ipv6 address 3ffe:b00:c21:1::56/127
router(config-if)#tunnel source fastethernet 0/0
router(config-if)#tunnel destination 192.168.20.1
router(config-if)#tunnel mode ipv6ip
In the example above, notice that the router’s prompt is in “interface configuration” mode when the “tunnel source” command is being used; and the IPv4 address of the fastethernet 0/0 interface is being used as the source address for packets in the tunnel.
Now, if you need to remove the source address from a tunnel interface, use the word “no” in front of the command like you see below:
router(config-if)#no tunnel source
I hope this article was very informative and helped you quickly understand the usage of the “tunnel source” Interface configuration command. If you need to learn more; I suggest you visit my website, were you’ll find the latest information regarding Cisco IPv6 Design and Implementation Techniques.
To your success,
Charles Ross
CCNP #CSCO10444244