# ICMP protocol
---
protocol: &icmp
  name: icmp
  longname: Internet Control Message Protocol
  osilayer: 3
  fields:
    - field: type
      length: 1
    - field: code
      length: 1
    - field: checksum
      length: 2
    - field: roh
      desc: rest of header
      length: 4
    - field: data
      optional: true