what are the icmp types?
['Type 0 — Echo Reply.', 'Type 1 — Unassigned.', 'Type 2 — Unassigned.', 'Type 3 — Destination Unreachable.', 'Type 4 — Source Quench (Deprecated)', 'Type 5 — Redirect.', 'Type 6 — Alternate Host Address (Deprecated)', 'Type 7 — Unassigned.']