Real-World Case Study
Acme, Inc. has decided to use a link-state routing protocol for dynamic routing between its LANs and the remote offices, which are connected over the WANs. The link-state protocol the company has chosen is OSPF. Each of the routers that has connections to the LAN and WAN subnets will learn about and advertise OSPF routes with its OSPF neighbors.
The branch offices will have a default route that points toward the headquarters’ routers, and at the headquarters’ site, they will use a default route that points toward the service provider. Acme, Inc. itself will not be using BGP, but its WAN and Internet service provider, which is interacting with other service providers, will use BGP.
The WAN connection to one of the remote offices is very low bandwidth and is prone to becoming congested with traffic. It also occasionally drops all connection to the remote office’s router. Acme, Inc., has decided to use traffic shaping as part of the QoS configuration to attempt to ensure that the link is used more sparingly and is not overwhelmed with traffic during key business hours.