Layer 3 Routing Commands 1454Command HistoryDescription revised in 6.3.5 release.ip helper-address (interface configuration)Use the ip helper-address (interface configuration) command to configurethe relay of certain UDP broadcast packets received on a specific interface. Todelete a relay entry on an interface, use the no form of this command.Syntaxip helper-address {server-address | discard} [dest-udp-port | dhcp | domain| isakmp | mobile ip | nameserver | netbios-dgm | netbios-ns | ntp | pim-auto-rp | rip | tacacs | tftp | time]no ip helper-address [server-address | discard] [dest-udp-port | dhcp |domain | isakmp | mobile-ip | nameserver | netbios-dgm | netbios-ns | ntp| pim-auto-rp | rip | tacacs | tftp | time]• server-address — The IPv4 unicast or directed broadcast address to whichrelayed UDP broadcast packets are sent. The server address cannot be anIP address configured on any interface of the local router.• discard — Matching packets should be discarded rather than relayed, evenif a global ip helper-address configuration matches the packet.• dest-udp-port — A destination UDP port number from 1 to 65535.• port-name — The destination UDP port may be optionally specified by itsname. Whether a port is specified by its number or its name has no effecton behavior. The names recognized are as follows: dhcp (port 67), domain(port 53), isakmp (port 500), mobile-ip (port 434), nameserver (port 42),netbios-dgm (port 138), netbios-ns (port 137), ntp (port 123), pim-auto-rp (port 496), rip (port 520), tacacs (port 49), tftp (port 69), and time(port 37). Other ports must be specified by number.Default ConfigurationNo helper addresses are configured.Command ModeInterface Configuration (VLAN) mode.
