Belongs to link-state routing protocol

SPF (SPF)

It belongs to the link-state routing protocol and is a public standard, which theoretically has no limit on the size of the network; supporting the hierarchical design of the network, the network can be divided into two layers.

Layers are distinguished by the concept of "region".

After zoning, you can bring the following benefits:

1. Save system resources for each device in the area

(after the large area is divided, there will be less database content in the small area.)

(all routers in the same area, the database is exactly the same)

2. Enhance the stability of OSPF network.

(adverse effects of an unstable link, only in the same area)

(spread in the medium and will not affect other areas)

-backbone area

-non-backbone area

All non-backbone members must be directly connected to the backbone area in order to communicate normally.

Routers are also divided into different types because of the existence of areas:

-backbone router

Routers in which all links belong to the backbone area

-non-backbone router

Routers in which all links belong to non-backbone areas

-area Border Router (*) [ABR:area border router]

Both backbone and non-backbone areas must be connected.

-Autonomous system boundary router [ASBR:]

A router that has the ability to introduce external routes is called OSPF's ASBR.