ccna 200-301 network simulator tools today catalog

ccna 200-301 network simulator tools today catalog.Figure 2V-2 Correspondence between the two models2.4.1 Network Access Layer***The functions of the NetworkAccess layer (NAL) include the mapping of IP addresses to physical hardware addresses, and the encapsulation of 1P packets into frames. Based on the network interfaces of different hardware types, the NetworkAccess layer defines the connections to the physical media. The network access layer contains the addresses of the data link layer, as used for Ethernet . On is the MAC address, and in Figure 2-4-1, you can see the source MAC address, and the destination MAC address of the data frame. This layer is the most TCP / IP model of the27''low layer, responsible for receiving 1P datagrams from the IP layer and sending IP datagrams out through the low-level physical network, or receiving physical frames from the low-level physical network, decapsulating them to produce IP datagrams and handing them to the IP layer for processing2.4.2 INTERNET LAYER*** The main functions of the InterNetwork Layer (Internet) include three areas.. First, processing packet delivery requests from the transport layer: loading packets into IP datagrams, populating the headers, selecting the path to the destination node, and then sending the datagram to the appropriate network interface.. Second, processing incoming datagrams: first checking the legality of the datagram, then performing routing, and if the datagram has reached the destination node (the local machine), removing the header and giving the data portion of the IP message to the appropriate transport layer protocol; if the datagram has not yet reached the destination node, forwarding the datagram.. Third, processing ICMP (InternetControl MessageProtocol, Inter-network Control Message Protocol) messages: that is, dealing with the network's routingselection, traffic control, and congestion control. The Internet layer of the TCP/IP network model is very similar in function to the network layer of the ISO/OSI reference model. The protocols on the inter-network layer are as follows.