Internet Control Message Protocol (ICMP) ParametersLast Updated 2020-09-25 Available Formats XML HTML Plain text Registries included below ICMP Type Numbers Code Fields 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 Type 8 — Echo Type 9 — Router Advertisement Type 10 — Router Selection
