Difference between RIP and OSPF

The advantages and disadvantages of RIP and OSPF are compared. ospf and rip are compared: the rip Protocol is the distance vector routing selection protocol, and the measurement standard (metric) of the selected route is the number of hops, the maximum number of hops is 15. If the number of hops is greater than 15, the packet is discarded. The ospf protocol is the link-State routing selection protocol. The measurement standard of the routing is bandwidth and latency. Limitations of www.2cto.com RIP problems arising from the use of large networks: 15 hop limits of RIP, routes over 15 hops are considered inaccessible RIP cannot support Variable Length Subnet Mask (VLSM ), as a result, IP Address Allocation is inefficient and the whole route table is broadcast cyclically. Applications in low-speed links and wide area networks will cause a lot of problems. The convergence speed is slower than OSPF, it takes several minutes for a large network to converge. RIP does not have the concept of network latency and link overhead. routing is based on the number of hops. A route with a small number of hops is always selected as the best route. Even if a long route has a low latency and overhead, RIP has no region, route aggregation cannot be performed on any bit. Some enhanced functions are introduced into the new version r12002 of RIP. r00002 supports VLSM, authentication, and multicast update. However, the limit on the number of hops and slow convergence of r12002 make it not suitable for large networks. Compared with RIP, OSPF is more suitable for large networks: no limit on the number of hops supports variable-length Subnet Mask (VLSM) send link status updates using multicast and trigger updates when link status changes. This improves bandwidth utilization and accelerates convergence. It has the following advantages: 1. OSPF is a real LOOP-FREE (no routing self-ring) routing protocol. Derived from the advantages of the algorithm itself. (Link status and Shortest Path Tree Algorithm) 2. Fast OSPF convergence speed: route changes can be transmitted to the entire Autonomous System in the shortest time. 3. The concept of area Division is proposed. After the autonomous system is divided into different regions, the route information digest between regions greatly reduces the number of route information to be transmitted. In addition, the routing information does not expand rapidly as the network size expands. Www.2cto.com 4. Minimize the Protocol overhead. See: 1) The hello messages without routing information are sent regularly to discover and maintain the neighbor relationship, which is very short. The update mechanism is triggered when packets containing route information are sent. (Sent only when there is a route change ). However, to enhance the robustness of the Protocol, all requests are resold once every 1800 seconds. 2) In broadcast networks, multicast addresses (rather than broadcasts) are used to send packets, reducing interference with other network devices that do not run ospf. 3) in various networks (broadcast, NBMA) that can be accessed by multiple access, the number of Route switching (synchronization) times between routers in the same network segment is changed from O (N * N) the number of times is reduced to O (N. 4) propose the STUB region concept so that the introduced ASE route will not be transmitted in the STUB region. 5) supports route aggregation on the ABR (Regional Border Router) to further reduce route information transmission between regions. 6) in the point-to-point interface type, OSPF over On Demand Circuits is configured so that ospf no longer regularly sends hello packets and regularly updates route information. Update information is sent only when the network topology changes. 5. Provide more trusted routing choices by strictly dividing the route levels (which can be divided into four poles. 6. Good security. ospf supports interface-based plaintext and md5 verification. 7. OSPF can adapt to a variety of networks, with a maximum of thousands. Disadvantages of OSPF: 1. complicated configuration. Due to the complexity of network area division and network attributes, the network analyst must have a high level of network knowledge to configure and manage the OSPF network. Www.2cto.com 2. Weak routing load balancing capabilities. Although OSPF can automatically generate the interface routing priority based on the Interface speed and connection reliability, OSPF only selects the forwarding with a higher priority for routes with different priorities for the same purpose, routes with different priorities cannot be used for load balancing. Only those with the same priority can achieve the purpose of Server Load balancer. Unlike in the case of VPN, traffic can be automatically matched based on different priorities.
Ospf and isis have many similarities, both of which are link-State Routing Protocols. SPF algorithms are used for fast convergence of VSLM. There is no difference in purpose. In terms of protocol implementation, OSPF is deployed on the TCP/IP protocol cluster, runs on the IP layer, and the port number is 89. based on iso clns, ISIS is designed to implement iso clnp routing, later, we added support for IP routing. From specific details: 1: The region design is different. OSPF uses a backbone AREA0 and a non-backbone region, and the non-backbone region must be connected to AREAO. ISIS is a hierarchical structure composed of L1 L2 L12 routers. It uses a lot less LSP and has better scalability in the same region than OSPF. 2 OSPF has many LSA types, which are complex and resource-consuming, while ISIS has fewer LSP types. Therefore, ISIS is better at CPU usage and route update processing. The timer of www.2cto.com 3 isis allows finer adjustment than OSPF, which can increase the convergence speed. 4. The OSPF data format is not easy to add new things. To add new things, a new LSA is required, while ISIS can easily expand by adding TLV, including IPV6 support. 5. In terms of selection, ISIS is more suitable for carrier-level networks, while OSPF is very suitable for enterprise-level networks.