Basic remote connectivity

- [Instructor] While a lot of the routing tests…will cover LAN and internet routing,…an infinitely important topic is connecting remote networks.…There's quite a variety of methods,…even more than we will discuss below.…Multiprotocol Label Switching, or MPLS,…is a large enterprise in service provider technique…that can segregate network traffic.…MPLS uses a shim header, which is a 32-bit label…that is inserted between a frame's layer three…and layer two header.…

It's also sometimes called a layer 2.5 protocol…for this reason.…MPLS routers use these labels to make forwarding decisions…instead of IP addresses.…MPLS provides connectivity to customers in one of two ways.…Either via layer two or layer three.…Layer two MPLS virtual private networks hand connectivity…to edge customer routers via layer two.…Even though these networks may be geographically diverse,…the customer connections will appear to be plugged…into the same layer two switch.…

Layer three MPLS VPNs will establish a peering relationship,…generally using multiprotocol BGP…