Dell BigIron RX Series, Руководство по настройке

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BigIron RX Series Configuration Guide 197
53-1002253-01
Configuring forwarding parameters
7
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Host – The destination network or subnet of the packet is directly connected to the device, but
the host specified in the destination IP address of the packet is not on the network.
•
Network – The device cannot reach the network specified in the destination IP address of the
packet.
•
Port – The destination host does not have the destination TCP or UDP port specified in the
packet. In this case, the host sends the ICMP Port Unreachable message to the device, which
in turn sends the message to the host that sent the packet.
•
Protocol – The TCP or UDP protocol on the destination host is not running. This message is
different from the Port Unreachable message, which indicates that the protocol is running on
the host but the requested protocol port is unavailable.
•
Source-route-failure – The device received a source-routed packet but cannot locate the
next-hop IP address indicated in the packet’s Source-Route option.
You can disable the device from sending these types of ICMP messages on an individual basis.
NOTE
Disabling an ICMP unreachable message type does not change the device’s ability to forward
packets. Disabling ICMP unreachable messages prevents the device from generating or forwarding
the unreachable messages.
To disable all ICMP Unreachable messages, enter the following command.
BigIron RX(config)# no ip icmp unreachable
Syntax: [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), all
types of ICMP Unreachable messages listed above are disabled. If you want to disable only
specific types of ICMP Unreachable messages, you can specify the message type. To disable
more than one type of ICMP message, enter the no ip icmp unreachable command for each
messages 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 But
Don’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 leave
the other types of ICMP Unreachable messages enabled, enter the following commands instead of
the command shown above.
BigIron RX(config)# no ip icmp unreachable host
BigIron RX(config)# no ip icmp unreachable network
If 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.