Question: what are the icmp type and code numbers?
Answer: 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.