1.开放最短路径优先(OSPF)：
OSPF使用链接状态路由算法。使用路由器中可用的链路状态信息，它构造拓扑，在该拓扑中拓扑确定用于路由决策的路由表。它支持变长子网掩码和无类域间路由寻址模型。由于它使用Dijkstra的算法，因此它会为每条路线计算最短路径树。 OSPF(首先是开放式最短路径)的主要优点是它自己处理错误检测，并且使用多播寻址在广播域中进行路由。
2.内部网关路由协议(IGRP)：
IGRP使用距离矢量协议(内部)在系统内交换数据。它支持每个节点的多个度量标准，包括延迟，负载和带宽，以便比较组合为单个度量标准的2条路由。 IGRP的端口号是9，该端口用于通信，默认情况下，每90秒更新一次路由信息。
OSPF和IGRP之间的区别：
| SR.NO | OSPF | IGRP |
|---|---|---|
| 1. | OSPF stands For Open Shortest Path First. | IGRP Stands For Interior Gateway Routing protocol. |
| 2. | OSPF works on Dijkstra Algorithm. | IGRP works on Bellman ford Algorithm. |
| 3. | It is a link state protocol. | It is a distance vector protocol. |
| 4. | It is basically use for larger size organization in the network. | It is basically use for medium to larger size organization in the network. |
| 5. | There is no such restriction on the hop count. | It allow maximum hop count upto 255. |
| 6. | It is a more intelligent routing protocol than IGRP. | It is not more intelligent routing protocol. |
| 7. | OSPF routing protocol creates three Table in the router: Neighbor Table, Database Table, Routing Table. |
IGRP routing protocol creates three table In the router : Neighbor Table, Topology Table, Routing Table. |
| 8. | It’s dministrative distance is 110. | It’s administrative distance is 100. |
| 9. | It Is a Industry standard routing protocol. | It Is a Cisco standard routing protocol. |
| 10. | It calculates the metric in terms of bandwidth. | It calculates the metric In terms of bandwidth, load and delay. |