network host -k8凯发

1. application layer
   1. requests connections to remote hosts
   2. generates the data
   3. dhcp protocol
      1. set a ip address for computer
   4. dns protocol
      1. transfer url to ip address
         1. post data to website
   5. http protocol
      1. get data from website
2. transport layer(tcp/udp)
   1. establishes connections with remote host
      1. udp protocol
      2. tcp protocol
3. network layer(ip)
   1. transfer packets with virtual (ip) addresses
      1. ipv4
      2. ipv6
      3. subnet mask
      4. ip data frame
4. data link layer(mac)
   1. transfers frames with physical (mac) addresses
5. physical layer
   1. encodes and transmits bits (transfer0/1 etc electrical signals)
   2. ethernet protocol
      1. define how to understand the meaning of the sequence of electrical signals
      2. data frame
         1. head
            1. who send the data, who would receive the data and data type
         2. data
      3. address resolution protocol (arp)
         1. broadcasting