What does “Destination Network Administratively Prohibited” signify in ICMP?

"Destination Network Administratively Prohibited" in ICMP indicates that a router or firewall is rejecting the packet due to specific administrative restrictions or configurations. This means that the device has the capability to receive traffic but has been configured to block certain types or sources of traffic. This is often a protective measure implemented in network infrastructures to prevent unauthorized access or unwanted communication.

When you receive this message, it clearly points to firewall rules or configurations rather than something like network overload, which would have different implications. It does not suggest a loss of routing capability – as would be the case with no route to host – or an issue with the routing table being corrupted. Instead, it specifically indicates that the packet is being intentionally blocked by administrative settings.