Disabling Icmp Messages - Dell PowerConnect B-RX Configuration Manual

7
Configuring forwarding parameters
NOTE
When you enable the device for zero-based subnet broadcasts, the device still treats IP packets with
all ones the host portion as IP subnet broadcasts too. Thus, the device can be configured to support
all ones only (the default) or all ones and all zeroes.
NOTE
This feature applies only to IP subnet broadcasts, not to local network broadcasts. The local network
broadcast address is still expected to be all ones.
To enable the device for zero-based IP subnet broadcasts in addition to ones-based IP subnet
broadcasts, enter the following command.
BigIron RX(config)# ip broadcast-zero
Syntax: [no] ip broadcast-zero

Disabling ICMP messages

The device is 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:
•
•
Disabling replies to broadcast ping requests
By default, the device is 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.
BigIron RX(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.
BigIron RX(config)# ip icmp echo broadcast-request
Disabling ICMP destination unreachable messages
By default, when the 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
device's response to the following types of ICMP Unreachable messages:
•
•
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Echo messages (ping messages) – The device replies to IP pings from other IP devices.
Destination Unreachable messages – If the device receives an IP packet that it cannot deliver
to its destination, the device discards the packet and sends a message back to the device that
sent the packet. The message informs the device that the destination cannot be reached by
the device.
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 Don't Fragment bit set in the IP Flag field, but the
device cannot forward the packet without fragmenting it.
BigIron RX Series Configuration Guide
53-1002253-01