How to allow snmp access to network topology mapper
It encapsulates its data directly in IP packets with protocol number 89. OSPF runs over Internet Protocol Version 4 (IPv4) and Internet Protocol Version 6 (IPv6), but does not use a transport protocol, such as UDP or TCP. An ABR maintains separate link-state databases for each area it serves and maintains summarized routes for all areas in the network. Such connections are maintained by an interconnecting router, known as an area border router (ABR). Each additional area must have a connection to the OSPF backbone area. While the identifications of other areas may be chosen at will, administrators often select the IP address of a main router in an area as the area identifier. By convention, area 0 (zero), or 0.0.0.0, represents the core or backbone area of an OSPF network. Areas are identified by 32-bit numbers, expressed either simply in decimal, or often in the same octet-based dot-decimal notation used for IPv4 addresses. OSPF divides the network into routing areas to simplify administration and optimize traffic and resource utilization. This provides a dynamic process of traffic load balancing between routes of equal cost. Cost factors may be the distance of a router ( round-trip time), data throughput of a link, or link availability and reliability, expressed as simple unitless numbers.
The OSPF routing policies for constructing a route table are governed by link metrics associated with each routing interface. It computes the shortest-path tree for each route using a method based on Dijkstra's algorithm. OSPF detects changes in the topology, such as link failures, and converges on a new loop-free routing structure within seconds. The topology is presented as a routing table to the Internet Layer which routes packets based solely on their destination IP address.
It gathers link state information from available routers and constructs a topology map of the network. OSPF is an interior gateway protocol (IGP) for routing Internet Protocol (IP) packets within a single routing domain, such as an autonomous system.
OSPF gathers link state information from available routers and constructs a topology map of the network. It uses a link state routing (LSR) algorithm and falls into the group of interior gateway protocols (IGPs), operating within a single autonomous system (AS). Open Shortest Path First ( OSPF) is a routing protocol for Internet Protocol (IP) networks.