Disabling Icmp Messages - Brocade Communications Systems FastIron SX 800 Configuration Manual

To enable the Layer 3 switch for zero-based IP subnet broadcasts in addition to ones-based IP subnet broadcasts, enter the following
command.
device(config)# ip broadcast-zero
device(config)# write memory
device(config)# end
device# reload
NOTE
You must save the configuration and reload the software to place this configuration change into
effect.
Syntax: [no] ip broadcast-zero

Disabling ICMP messages

Brocade devices are enabled to reply to ICMP echo messages and send ICMP Destination Unreachable messages by default.
You can selectively disable the following types of Internet Control Message Protocol (ICMP) messages:
• Echo messages (ping messages) - The Layer 3 switch replies to IP pings from other IP devices.
• Destination Unreachable messages - If the Layer 3 switch receives an IP packet that it cannot deliver to its destination, the
Layer 3 switch discards the packet and sends a message back to the device that sent the packet to the Layer 3 switch. The
message informs the device that the destination cannot be reached by the Layer 3 switch.
Disabling replies to broadcast ping requests
By default, Brocade devices are enabled to respond to broadcast ICMP echo packets, which are ping requests.
To disable response to broadcast ICMP echo packets (ping requests), enter the following command.
device(config)# no ip icmp echo broadcast-request
Syntax: [no] ip icmp echo broadcast-request
If you need to re-enable response to ping requests, enter the following command.
device(config)# ip icmp echo broadcast-request
Disabling ICMP destination unreachable messages
By default, when a Brocade device receives an IP packet that the device cannot deliver, the device sends an ICMP Unreachable message
back to the host that sent the packet. You can selectively disable a Brocade device response to the following types of ICMP Unreachable
messages:
• Host - The destination network or subnet of the packet is directly connected to the Brocade device, but the host specified in the
destination IP address of the packet is not on the network.
• 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.
• Administration - The packet was dropped by the Brocade device due to a filter or ACL configured on the device.
• Fragmentation-needed - The packet has the Do not Fragment bit set in the IP Flag field, but the Brocade device cannot
forward the packet without fragmenting it.
• 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 Brocade device, which in turn sends the message to the host that sent the packet.
FastIron Ethernet Switch Layer 3 Routing
53-1003627-04
Configuring IP parameters - Layer 3 switches
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