190 BigIron RX Series Configuration Guide53-1001810-01Configuring forwarding parameters7To disable all ICMP Unreachable messages, enter the following command.BigIron RX(config)# no ip icmp unreachableSyntax: [no] ip icmp unreachable [network | host | protocol | administration |fragmentation-needed | port | source-route-fail]• If you enter the command without specifying a message type (as in the example above), alltypes of ICMP Unreachable messages listed above are disabled. If you want to disable onlyspecific types of ICMP Unreachable messages, you can specify the message type. To disablemore than one type of ICMP message, enter the no ip icmp unreachable command for eachmessages type.• The network parameter disables ICMP Network Unreachable messages.• The host parameter disables ICMP Host Unreachable messages.• The protocol parameter disables ICMP Protocol Unreachable messages.• The administration parameter disables ICMP Unreachable (caused by Administration action)messages.• The fragmentation-needed parameter disables ICMP Fragmentation-Needed ButDon’t-Fragment Bit Set messages.• The port parameter disables ICMP Port Unreachable messages.• The source-route-fail parameter disables ICMP Unreachable (caused by Source-Route-Failure)messages.To disable ICMP Host Unreachable messages and ICMP Network Unreachable messages but leavethe other types of ICMP Unreachable messages enabled, enter the following commands instead ofthe command shown above.BigIron RX(config)# no ip icmp unreachable hostBigIron RX(config)# no ip icmp unreachable networkIf you have disabled all ICMP Unreachable message types but you want to re-enable certain types,you can do so entering commands such as the following.BigIron RX(config)# ip icmp unreachable hostBigIron RX(config)# ip icmp unreachable networkThe commands shown above re-enable ICMP Unreachable Host messages and ICMP NetworkUnreachable messages.Disabling ICMP redirect messagesYou can disable or re-enable ICMP redirect messages. By default, the device sends an ICMPredirect message to the source of a misdirected packet in addition to forwarding the packet to theappropriate router. You can disable ICMP redirect messages on a global basis or on an individualport basis.NOTEThe device forwards misdirected traffic to the appropriate router, even if you disable the redirectmessages.
