| Code | ICMP Type 3 : Detination Unreachable 一覧 | 
          
            | 0 | Net Unreachable | 
          
            | 1 | Host Unreachable | 
          
            | 2 | Protocol Unreachable | 
          
            | 3 | Port Unreachable | 
          
            | 4 | Fragmentation Needed and DF was Set | 
          
            | 5 | Source Route Failed | 
          
            | 6 | Destination Network Unknown | 
          
            | 7 | Destination Host Unknown | 
          
            | 8 | Source Host Isolated | 
          
            | 9 | Communication with Destination Network is
            Administratively Prohibited | 
          
            | 10 | Communication with Destinaltion Host is Administratively
            Prohibited | 
          
            | 11 | Destination Network Unreachable for ToS | 
          
            | 12 | Destination Host Unreachable for ToS | 
          
            | 13 | Communication Administratively Prohibited | 
          
            | 14 | Host Precedence Violation | 
          
            | 15 | Precedence cutoff in effect |