1108 Configuring L2 and L3 Relay Features
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]
Configure the relay of certain UDP broadcast packets
received on the VLAN routing interface(s). This command
takes precedence over an ip helper-address command given
in global configuration mode.
Specify the one of the protocols defined in the command
or the UDP port number.
•

server-address

— The IPv4 unicast or directed broadcast
address to which relayed UDP broadcast packets are sent.
The server address cannot be an IP address configured on
any interface of the local router.
•

dest-udp-port

— A destination UDP port number from 0
to 65535.
exit Exit to Global Config mode.
exit Exit to Privileged EXEC mode.
show ip helper-address
[vlan
vlan-id
]
View IP helper (L3 relay) settings for all interfaces or for
the specified VLAN routing interface.
show ip helper statistics View the number of DHCP and other UDP packets
processed and relayed by the UDP relay agent. To reset the
statistics to 0, use the clear ip helper statistics command.
Command Purpose