Cisco WS-C6506 Software Manual page 882

Configuring DHCP Snooping on a VLAN
Example 2: Enabling DHCP Snooping with an MSFC as a DHCP Relay Agent
This example shows how to configure the Multilayer Switch Feature Card (MSFC) as a relay agent with
the DHCP host tracking enabled.
In this example, the client is untrusted and accesses the switch with the MSFC as a relay agent. The
Note
MSFC relay agent switch connects to the MSFC DHCP server switch through a trusted trunk port.
This example shows how to configure the MSFC as a DHCP relay agent:
service dhcp
on int vlan 810
on int vlan 4094
This example shows how to configure the MSFC as a DHCP server:
service dhcp
ip dhcp excluded-address 192.168.80.241
!
ip dhcp pool net810
on int vlan 4094
The MSFC port is configured by the system as a DHCP-snooping trusted port.
Note
Figure 33-2
Figure 33-2
Client
Example 3: Enabling DHCP Snooping in Port-Based Mode
The following example shows how to enable DHCP snooping in port-based mode with a router as the
MSFC. The DHCP-snooping ACL is mapped to the host VLAN.
Console> (enable) set security acl map
Mapping in progress.
ACL dhcp successfully mapped to port(s) 1/2
Console> (enable) set security acl map dhcp 16
Mapping in progress.
ACL dhcp successfully mapped to VLAN 16.
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
33-8
ip address 192.168.80.241 255.255.255.0
ip helper-address 192.168.94.247
ip dhcp relay information trusted
ip address 192.168.94.241 255.255.255.0
network 192.168.80.0 255.255.255.0
ip address 192.168.94.247 255.255.255.0
shows the typical topology that is used when you configure the MSFC as a relay agent.
MSFC as a Relay Agent
Untrusted port
Catalyst 6500
DHCP
Relay Agent
Port 1/1
VLAN 810
Chapter 33 Configuring DHCP Snooping and IP Source Guard
Catalyst 6500
DHCP Server
Port 1/2
VLAN 4094
dhcp 1/2
OL-8978-04