4. Layer II - the Data Link Layer

• This layer has 2 sub-layers:
  1. The MAC (Media Access Control) layer, which makes sure that only one device will try to send data over a shared medium, ignores messages which are not intended to the computer, and drops damaged packets.
  2. the LLC (Logical Link Control) layer, which makes sure that both sides of every connection are synchronized, and does some error correction.
• The MAC layer is usually implemented in hardware and so poses no problem to Linux.

• 4.1. PPP
• 4.2. VPN - PPTP, PPPoE and L2TP
  • 4.2.1. ADSL and Cable under Linux
  • 4.2.2. DHCP
  • 4.2.3. Back to Cable TV Connections...

Written by Shlomi Fish