Nmap is a fantastic tool, but it helps with issues at an entirely different level than debugging routing issues. When you’re talking about L2 routing, firewall

Nmap is a fantastic tool, but it helps with issues at an entirely different level than debugging routing issues. When you’re talking about L2 routing, firewalling and NACLs, it is very, very likely that most packets are just silently dropped. In this case, nmap would just report that the host is not up (even if you tell nmap it is up).