So there is a little bit of confusion on the interwebz when it comes to understanding an IPSEC GRE tunnel. First off lets look at how it actually works. GRE works by encapsulating IP traffic inside of an IP packet and sends it across the wire to its destination where it is decapsulated and the inner-packet is than routed. GRE is commonly used to bridge two routed domains over a network outside of your administrative control. When using GRE over the public internet, security is a concern and therefore...

The following blog has been compiled to provide information for the different type(s) of WAN Technologies. Keep in mind that Ethernet is a fast growing WAN technology with companies moving to deploy VPLS, MPLS and TLS Circuits for WAN connectivity. As a Cisco network engineer you will still encounter legacy WAN connections. Digital Subscriber Line (DSL) technologies are fairly common in the United States and other developing nations that provide broadband to customers over existing telephone wire infrastructure. The is however the limitation of distance which basically means...