Seven layer model
Hub corresponds multiport repeater, bridge switcher corresponding to multiple ports.
Internet technical standards and protocols
ICMP ping command with the protocol, ARP is a protocol IP to MAC, RARP protocol is a MAC forwarding IP.
SNMP is the Simple Network Management Protocol, FTP and TFTP is a file server, but a reliable and an unreliable. The middle is sharing protocol, which Samba may be cross-platform.
TCP three-way handshake
tcp / ip protocol is reliable protocol, because the first connection is established.
DHCP protocol
DHCP is a protocol of the application layer.
DNS protocol
Because the distribution of digital ip is so difficult to remember domain name on the right side of this thing.
Classification network
Press according to topology and distribution points
General office with star-shaped junction, the switch is in the middle of the core nodes.
Network planning and hierarchical design
IP addresses special meaning
Wi-Fi
Wireless WAN: that we use 4G 3G traffic flow.
Wireless Metropolitan Area Networks: the already planning to category 4G3G.
Wireless LAN: Wifi
WPAN: Bluetooth
Network Access Technology
PSTN: dial-up, Internet can not call.
ISDN: When can call the Internet, 128k.
ADSL: home network, telephone line communication, will use some of the old district. Downlink: 8M Uplink: 512K
HFC: fiber.
IPV6
