Saluting all our R&S family members!
In today's blog post we are going to address OSPF, or the Open Shortest Path First protocol, a huge term found in the routing industry.
I can tell OSPF is one essential factor even in today's networking world not only because it's been around for quite some time now, but also from the amount of queries our esteemed users were kind enough to run on the Community. No more talking though - please find below an introduction on the Open Shortest Path First protocol!
BACKGROUND INFORMATION
The Open Shortest Path First (OSPF) protocol, developed by the Internet Engineering Task Force (IETF), is a link-state Interior Gateway Protocol (IGP). At present, OSPF Version 2, defined in RFC 2328, is intended for IPv4, and OSPF Version 3, defined in RFC 2740, is intended for IPv6.
TYPES OF ROUTERS
Please find below the most common router types used in OSPF:
TYPES OF PACKETS
Please find below the most common router types used in OSPF:
ROUTE CALCULATION
OSPF route calculation involves the following processes:
adjacency establishment;
route calculation.
Adjacency establishment
The adjacency establishment process is as follows:
1. the local and remote routers use OSPF interfaces to exchange Hello packets to establish a neighbor relationship;
2. the local and remote routers negotiate a master/slave relationship and exchange Database Description (DD) packets;
3. the local and remote routers exchange link state advertisements (LSAs) to synchronize their link state databases (LSDBs).
Route calculation
OSPF uses the shortest path first (SPF) algorithm to calculate routes, resulting in fast route convergence. OSPF uses an LSA to describe the network topology. A Type 1 LSA describes the attributes of a link between routers.
A router transforms its LSDB into a weighted, directed graph, which reflects the topology of the entire AS. All routers in the same area have the same graph.
THE BOTTOM LINE
A crucial aspect within Interior Gateway Protocols, OSPF can undoubtedly come in extremely handy whenever it needs to be deployed. More information on OSPF can be found by accessing this link.
Stay tuned to our weekly blog digest by subscribing to the Community blog and don't forget - we're here to help you solve any OSPF-related issue: https://forum.huawei.com/enterprise/en/Switch/forum/861.
