Reference Guide

Parameter Description
dest-udp-
port
A destination UDP port number from 0 to 65535.
port-name The destination UDP port may be optionally specified by its name. Whether a port is specified
by its number or its name has no eect on 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)
•
time (port 37)
Other ports must be specified by number.
To relay DHCP packets received on interface 1/0/2 to two DHCP servers, 192.168.10.1 and 192.168.20.1, use
the following commands:
(Extreme 220) #config
(Extreme 220) (Config) #interface 1/0/2
(Extreme 220)(interface 1/0/2)#ip helper-address 192.168.10.1 dhcp
(Extreme 220)(interface 1/0/2)#ip helper-address 192.168.20.1 dhcp
To relay both DHCP and DNS packets to 192.168.30.1, use the following commands:
(Extreme 220) #config
(Extreme 220) (Config) #interface 1/0/2
(Extreme 220)(interface 1/0/2)#ip helper-address 192.168.30.1 dhcp
(Extreme 220)(interface 1/0/2)#ip helper-address 192.168.30.1 dns
This command takes precedence over an ip helper-address command given in global configuration
mode. With the following configuration, the relay agent relays DHCP packets received on any interface
other than 1/0/2 and 1/0/17 to 192.168.40.1, relays DHCP and DNS packets received on 1/0/2 to
192.168.40.2, relays SNMP (Simple Network Management Protocol) traps (port 162) received on interface
1/0/17 to 192.168.23.1, and drops DHCP packets received on 1/0/17:
(Extreme 220) #config
(Extreme 220) (Config) #ip helper-address 192.168.40.1 dhcp
(Extreme 220) (Config) #interface 1/0/2
(Extreme 220)(interface 1/0/2)#ip helper-address 192.168.40.2 dhcp
(Extreme 220)(interface 1/0/2)#ip helper-address 192.168.40.2 domain
(Extreme 220)(interface 1/0/2)#exit
(Extreme 220) (Config) #interface 1/0/17
(Extreme 220)(interface 1/0/17)#ip helper-address 192.168.23.1 162
(Extreme 220)(interface 1/0/17)#ip helper-address discard dhcp
Routing Commands
ExtremeSwitching 200 Series: Command Reference Guide for version 01 .02.04.0007 561