Cisco CATALYST 2960

20-16
Catalyst 2960 and 2960-S Switches Software Configuration Guide, Release 15.0(1)SE
OL-26520-01
Chapter 20 Configuring DHCP and IP Source Guard Features
Configuring IP Source Guard
Enabling IP Source Guard
Begin in privileged EXEC mode.
To disable IP source guard with source IP address filtering, use the no ip verify source interface
configuration command.
To delete a static IP source binding entry, use the no ip source global configuration command.
This example shows how to enable IP source guard with source IP and MAC filtering on VLANs 10
and 11:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface gigabitethernet1/0/1
Switch(config-if)# ip verify source port-security
Switch(config-if)# exit
Switch(config)# ip source binding 0100.0022.0010 vlan 10 10.0.0.2 interface
gigabitethernet1/0/1
Switch(config)# ip source binding 0100.0230.0002 vlan 11 10.0.0.4 interface
gigabitethernet1/0/1
Switch(config)# end
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
interface interface-id Specify the interface to be configured, and enter interface configuration
mode.
Step 3
ip verify source
or
ip verify source port-security
Enable IP source guard with source IP address filtering.
Enable IP source guard with source IP and MAC address filtering.
When you enable both IP source guard and Port Security by using the ip
verify source port-security interface configuration command, there are
two caveats:
• The DHCP server must support option 82, or the client is not
assigned an IP address.
• The MAC address in the DHCP packet is not learned as a secure
address. The MAC address of the DHCP client is learned as a secure
address only when the switch receives non-DHCP data traffic.
Step 4
exit Return to global configuration mode.
Step 5
ip source binding mac-address vlan
vlan-id ip-address inteface interface-id
Add a static IP source binding.
Enter this command for each static binding.
Step 6
end Return to privileged EXEC mode.
Step 7
show ip verify source [interface
interface-id]
Verify the IP source guard configuration.
Step 8
show ip source binding [ip-address]
[mac-address] [dhcp-snooping | static]
[inteface interface-id] [vlan vlan-id]
Display the IP source bindings on the switch, on a specific VLAN, or on
a specific interface.
Step 9
copy running-config startup-config (Optional) Save your entries in the configuration file.