Enabling Ip Source Guard - Cisco Catalyst 3120 Software Manual

Configuring IP Source Guard
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Enabling IP Source Guard

Beginning in privileged EXEC mode, follow these steps to enable and configure IP source guard on an
interface.
Command
Step 1
configure terminal
Step 2 interface interface-id
Step 3 ip verify source
or
ip verify source port-security
Step 4
exit
Step 5
ip source binding mac-address vlan
vlan-id ip-address inteface interface-id
Step 6 end
Step 7
show ip verify source [interface
interface-id]
Cisco Catalyst Blade Switch 3120 for HP Software Configuration Guide
21-18
When configuring IP source guard on interfaces on which a private VLAN is configured, port
security is not supported.
IP source guard is not supported on EtherChannels.
You can enable this feature when IEEE 802.1x port-based authentication is enabled.
If the number of hardware entries exceeds the maximum available, the CPU usage increases.
In a switch stack, if IP source guard is configured on a stack member interface and you remove the
the configuration of that switch by entering the no switch stack-member-number provision global
configuration command, the interface static bindings are removed from the binding table, but they
are not removed from the running configuration. If you again provision the switch by entering the
switch stack-member-number provision command, the binding is restored.
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."
Purpose
Enter global configuration mode.
Specify the interface to be configured, and enter interface configuration
mode.
Enable IP source guard with source IP address filtering.
Enable IP source guard with source IP and MAC address filtering.
Note
Return to global configuration mode.
Add a static IP source binding.
Enter this command for each static binding.
Return to privileged EXEC mode.
Display the IP source guard configuration for all interfaces or for a
specific interface.
Chapter 21
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.
Configuring DHCP Features and IP Source Guard
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