网络教程(9)ARP。IP和以太网间映射

question: how does a knows that SFO is the right place to send as Ethernet frame

 

subnet Mask:

its just anotherway of saying that the prefix length is the slash 24

 

 

这张图的意思:

if its not on 192.168.9.something… then send it to 192.168.9.1 router

 

我们知道了我们想发给SFO的IP地址 但是我们需要知道怎么到它的MAC地址

 

need a protocol that use to send a broadcast to everybody on ethernet network asking who own this IP address

 

Address Resolution Protocol(ARP):

 

broadcast addres : 255.255.255.255 ..1111 1111…  (ff ff ff ff)

 

ethertype 0806是ARP协议

protocoltype 0800 是IP