You need OSPF or IS-IS to distribute link information such as reserved, unreserved and used bandwidth, metric, link colouring information.These informations are used by CSPT ( Constraint based shortest path first ) algorithm.
OSPF Prefix Suppression helps to company to use 200 routers in their network without any problem. You can think that, some companies use more than 200 routers in their OSPF network, why this post is special? You will understand why in 10 minutes.
OSPF and MPLS is most commonly used two technologies in an MPLS VPN environment. In this post I will share a mini design scenario with you and ask couple questions about the fictitious company architecture.
– In the below picture, where should you place an OSPF ABR (Area Border Router) to scale OSPF design ? Why ?