List and set data link type

“-L/--list-data-link-types“ option is used to list available data link types: 

  1. # tcpdump -L
  2. Data link types for enp0s3 (use option -y to set):
  3.   EN10MB (Ethernet)
  4.   DOCSIS (DOCSIS) (printing not supported)

Beware that the output may be different if the interface works in different modes (e.g., monitor mode or not).

As prompted, “-y datalinktype/--linktype=datalinktype“ option can be used to set data link type to capture packets: 

  1. # tcpdump -y EN10MB