Switch

Switch

1. Switches operate at the link layer

2. Network-layer addresses

   • (for example, Internet IP addresses) and link-layer addresses (that is, MAC addresses), need to translate between them.
     • For the Internet, this is the job of the Address Resolution Protocol (ARP) [RFC 826

3. switch link-layer frame segments de information

4. MAC Addresses

   • it is not hosts and routers that have link-layer addresses but rather their adapters (that is, network interfaces) that have link-layer addresses
     • Ob of the link-layer switch is to carry datagrams between hosts and routers; a switch
       • A link-layer address is variously called a LAN address, a physical address, or a MAC address