How to configure OSPF in the Cisco IOS. By David Davis - January 8, 2009 The OSPF dynamic routing protocol is probably the most popular LAN routing protocol today. OSPF can scale to the largest LANs but can also start out small. While OSPF can be complex to configure, its basic configuration isn't difficult. Let's learn how to configure OSPF in the Cisco IOS. What do you need to know about OSPF? Before you configure OSPF, there are three things you should know about it first. Here they are: OSPF stands for open shortest path first. With OSPF, every router has its own unique "picture" (topology map) of the network. What features does OSPF offer? OSPF offers the following features, that are found in a number of routing protocols: How do you configure OSPF in the Cisco IOS? To configure OSPF in the Cisco IOS, just follow these steps: Set the bandwidth on your interfaces using the bandwidth command Router (config-if)# bandwidth XX (where XX signifies the bandwidth of the WAN connection) Router (config)# router ospf {process-ID#}
IS-IS Network Protocol Basics. IS-IS is a link-state interior gateway routing protocol. Like OSPF, IS-IS runs the Dijkstra shortest-path first (SPF) algorithm to create a database of the network’s topology and, from that database, to determine the best (that is, shortest) path to a destination. Unlike OSPF, which was developed and standardized by the Internet Engineering Task Force (IETF), IS-IS is an ANSI ISO protocol and was originally based on the Digital Equipment Corporation DECNET Phase V Network Technology. IS-IS uses a slightly different terminology than OSPF for naming its protocol packets. The packets that IS-IS routers send to each other describing the network topology are called link-state protocol data units (link-state PDUs, or LSPs).
In addition to describing the network topology that the router knows about, the link-state PDUs include IP routes, checksums, and other information. Because it was developed as part of the OSI network protocols and not part of TCP/IP, IS-IS doesn’t use IP addresses. BGPexpert.com - Your friendly neighborhood BGP expert is now IPv6 enabled. BGP Reports.