Network BASICS (2)

I. Physical Layer 1, function: 2, twisted pair wires: The network cable exceeds 100 meters, and the signal will be weakened. It can be solved through a switch. The switch can not only forward data frames, but also reshape the signal, it can extend the connection distance of the network cable. 3. The optical fiber transmission distance is long, and the signal attenuation is small. The unit is kilometers. 4. Wired medium (twisted pair wire, optical fiber) and wireless medium (

I. Physical Layer 1, function: 2, twisted pair wires: The network cable exceeds 100 meters, and the signal will be weakened. It can be solved through a switch. The switch can not only forward data frames, but also reshape the signal, it can extend the connection distance of the network cable. 3. The optical fiber transmission distance is long, and the signal attenuation is small. The unit is kilometers. 4. Wired medium (twisted pair wire, optical fiber) and wireless medium (

I. Physical Layer

1. functions:

2. Twisted Pair wires: if the network cable exceeds 100 meters, the signal will be weakened and can be solved through a switch. The switch can not only forward data frames, but also reshape the signal to extend the connection distance of the network cable;

3. Long optical fiber transmission distance and small signal attenuation, in kilometers;

4. Wired media (twisted pair wires, optical fiber cables), wireless media (Wireless WIFI, infrared, etc)

2. Data Link Layer

1. vswitch (generally 24 ports) and PC connection Diagram

2. Role of the vswitch:

A. waveform reconstruction to extend the communication distance;

B. Data Frame Forwarding;

4. The MAC mark of the data link layer includes:
A. source MAC address
B. Target MAC address

5. Forwarding principles of vswitches:
A. There is A Mac address table in the vswitch as follows:

Mac address port number h

Save the source MAC address and port number

B. The switch sends broadcasts to all ports (the MAC address of the switch as the Broadcast Sender is FF: FF)

C. The target MAC responds to the source, and the source host sends unicast messages to the target MAC address.

The network connecting a vswitch/vro to a PC is Ethernet (LAN)