CCNP - GRE Tunnels

Basics

 * Used to tunnel packets.
 * Accomplished by encapsulating them.
 * Created to be as generic as possible.

GRE Configuration
1. Router(config)#interface tunnel [x] 2. Router(config-if)#ip address [ip] [subnet mask] 3. Router(config-if)#tunnel source [source interface] 4. Router(config-if)#tunnel destination [destination ip]
 * 1) Creates the tunnel interface.
 * 2) Adds an IP address to the tunnel interface.
 * 3) Designates the start point of the tunnel.
 * 4) Designates the destination of the tunnel.
 * 5) Note: Destination IP should be the end-point's physical interface, not the end-point's tunnel IP.

GRE Over IPSec
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