ICMP protocol related

ICMP is in the third layer in the OSI model, and therefore does not have a port number.
A protocol separate and distinct from TCP/IP. As such it can be toggled to pass through or be blocked by routers, but not by opening or closing TCP/IP ports.
ICMP is incapsulated in an IP datagram and is transported that way.
ICMP Destination Unreachable
Lists of reserved ports,ICMP types and codes, and Internet protocols