Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 62)

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:
• 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.
• 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.
Disabling ICMP messages
62 FastIron Ethernet Switch Layer 3 Routing Configuration Guide
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