Reference Guide

IPv4 Addressing | 469

To view if ICMP redirect messages are sent on the interface, use the show config command in the

INTERFACE mode. If it is not listed in the

show config command output, it is enabled. Only nondefault

information is displayed in the

show config command output.

UDP Helper

UDP helper allows you to direct the forwarding IP/UDP broadcast traffic by creating special broadcast

addresses and rewriting the destination IP address of packets to match those addresses. Configurations

using this feature are described in the section Configurations Using UDP Helper.

Configuring UDP Helper

Configuring FTOS to direct UDP broadcast is a two-step process:

1. Enabling UDP Helper.

2. Configuring a Broadcast Address.

Important Points to Remember about UDP Helper

• The existing command ip directed broadcast is rendered meaningless if UDP helper is enabled on the

same interface.

• The broadcast traffic rate should not exceed 200 packets per second when UDP helper is enabled.

• You may specify a maximum of 16 UDP ports.

• UDP helper is compatible with IP helper (

ip helper-address):

• UDP broadcast traffic with port number 67 or 68 are unicast to the DHCP server per the

helper-address configuration whether or not the UDP port list contains those ports.

• If the UDP port list contains ports 67 or 68, UDP broadcast traffic forwarded on those ports.