This lesson we have to learn about the network layer devices. For network layer device that we we are no strangers, the most important is the router. That this lesson we have to learn about its router and its internal structure a forwarding process.
Dedicated computer first then it is a router with multiple input ports and multiple output ports, it is the task of forwarding packets. Ah just because it has multiple input and output ports, we can make this router connected to multiple hosts and connected to the multiple networks.
Well, this is an internal block diagram of a router. We can see that it is divided into two parts, one part routing, packet forwarding is a part. Then this routing part of it, also called the control section.
That the core of this part of the building, we can see that routing the largest choice of word processor. Ah this routing function it is based on its selected a routing protocol, ah protocol such as RIP or OSPF protocol, etc., to construct a complete routing table. Ah talked about because these two agreements before us, to construct the routing table entry is actually not the same. That way constructed by the table after it ah can periodically or regularly and adjacent routers exchange routing information, but it can also continue to update and maintain the routing table. So this routing part of it is to build a complete routing table and services.
That we are going to look at this second part. The second part of it is part of the packet forwarding, packet forwarding it that this in turn consists of three parts. It is the first part a plurality of input ports, the second part is the middle of the switch fabric. The third is a plurality of output ports. In that packet forwarding this piece of it, of course, the core switching fabric.
Exchange structure according to its function it is