DHCP/BOOTP Relay Configuration Examples

The following example shows how to permit UDP broadcasts from hosts on networks 191.168.1.255 and 192.24.1.255 to reach servers on other networks:

System(rw)->configure
System(rw-config)->ip forward-protocol udp
System(rw-config)->interface vlan.0.1
System(rw-config-intf-vlan.0.1)->ip helper-address 192.168.1.255
System(rw-config-intf-vlan.0.1)->exit
System(rw-config)->interface vlan.0.2
System(rw-config-intf-vlan.0.2)->ip helper-address 192.24.1.255

This example configures several Option 82 sub-options to be included in the DHCP relay agent information packets. This example also shows how you would use the link selection option to tell the DHCP server to assign leases from different sub-networks, depending on information received in the DHCP client request. For example, when the relay agent receives a DHCP client request from a host with MAC address 002654AF123B, the relay agent sets the DHCP relay agent information link selection option value to 10.180.2.0. If the MAC address were 00301E44AC12, the option value would be set to 10.180.3.0.

System(su)->configure
System(su-config)->interface vlan.0.10
System(su-config-intf-vlan.0.10)->ip address 10.180.1.8 255.255.255.0 primary
System(su-config-intf-vlan.0.10)->ip address 10.180.2.8 255.255.255.0 secondary
System(su-config-intf-vlan.0.10)->ip address 10.180.3.8 255.255.255.0 secondary
System(su-config-intf-vlan.0.10)->ip address 10.180.4.8 255.255.255.0 secondary
System(su-config-intf-vlan.0.10)->ip directed-broadcast
System(su-config-intf-vlan.0.10)->ip helper-address 11.5.255.255 global
System(su-config-intf-vlan.0.10)->ip dhcp relay information option
System(su-config-intf-vlan.0.10)->ip dhcp relay information option vpn
System(su-config-intf-vlan.0.10)->ip dhcp relay information option remote-id Shrewsbury
System(su-config-intf-vlan.0.10)->ip dhcp relay information option circuit-id engineering
System(su-config-intf-vlan.0.10)->ip dhcp relay information option link-selection 10.180.2.0 mac 002654AF123B
System(su-config-intf-vlan.0.10)->ip dhcp relay information option link-selection 10.180.2.0 vendor-id "MSFT 5.0"
System(su-config-intf-vlan.0.10)->ip dhcp relay information option link-selection 10.180.3.0 mac 00301E44AC12
System(su-config-intf-vlan.0.10)->ip dhcp relay information option link-selection 10.180.4.0 mac 001CC504BC34
System(su-config-intf-vlan.0.10)->exit
System(su-config)->