Cisco Catalyst 3750-E - Enabling Ip Source Guard

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Catalyst 3750-E and 3560-E Switch Software Configuration Guide
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Chapter 22 Configuring DHCP Features and IP Source Guard
Configuring IP Source Guard
To remove the binding from the running configuration, you must disable IP source guard before
entering the no switch provision command. The configuration is also removed if the switch reloads
while the interface is removed from the binding table. For more information about provisioned
switches, see the Chapter 5, “Managing Switch Stacks.”
Enabling IP Source Guard
Beginning in privileged EXEC mode, follow these steps to enable and configure IP source guard on an
interface.
To disable IP source guard with source IP address filtering, use the n
o ip verify source interface
configuration command.
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.
Note 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.