Dell PowerConnect M6348 Configuration Manual page 94

Example 2: Configure IP Helper Globally (DHCP)
To relay DHCP packets received on any interface to two DHCP servers (10.1.1.1 and 10.1.2.1), use the
following commands:
console (config)#ip helper-address 10.1.1.1 dhcp
console (config)#ip helper-address 10.1.2.1 dhcp
Example 3: Enable IP Helper Globally (UDP)
To relay UDP packets received on any interface for all default ports (Table 2) to the server at 20.1.1.1, use
the following commands:
console (config)#ip helper-address 20.1.1.1
Example 4: Enable IP Helper on an Interface on a Server (DHCP)
To relay DHCP packets received on interface 2/1 to two DHCP servers, 192.168.10.1 and 192.168.20.1,
use the following commands:
console(config-if-2/g1)#ip helper-address 192.168.10.1 dhcp
console(config-if-2/g1)#ip helper-address 192.168.20.1 dhcp
Example 5: Enable IP Helper on an Interface on a Server (DHCP and DNS)
To relay DHCP and DNS packets to 192.168.30.1, use the following commands:
console(config-if-2/g1)#ip helper-address 192.168.30.1 dhcp
console(config-if-2/g1)#ip helper-address 192.168.30.1 dns
Example 6: Enable IP Helper on Multiple Interfaces
With the following configuration, the relay agent relays:
• DHCP packets received on any interface other than 2/5 and 2/6 to 192.168.40.1
• DHCP and DNS packets received on 2/5 to 192.168.40.2
• SNMP traps (port 162) received on interface 2/6 to 192.168.23.1
• Drops DHCP packets received on 2/6
console(config)#ip helper-address 192.168.40.1 dhcp
console(config-if-2/g5)#ip helper-address 192.168.40.2 dhcp
console(config-if-2/g5)#ip helper-address 192.168.40.2 domain
console(config-if-2/g6)#ip helper-address 192.168.23.1 162
console(config-if-2/g6)#ip helper-address discard dhcp
94
Routing Configuration