23-12
Catalyst 2960 and 2960-S Switch Software Configuration Guide
OL-8603-09
Chapter 23 Configuring Port-Based Traffic Control
Configuring Port Security
• When you enable port security on an interface that is also configured with a voice VLAN, set the
maximum allowed secure addresses on the port to two. When the port is connected to a Cisco IP
phone, the IP phone requires one MAC address. The Cisco IP phone address is learned on the voice
VLAN, but is not learned on the access VLAN. If you connect a single PC to the Cisco IP phone,
no additional MAC addresses are required. If you connect more than one PC to the Cisco IP phone,
you must configure enough secure addresses to allow one for each PC and one for the phone.
• When a trunk port configured with port security and assigned to an access VLAN for data traffic and
to a voice VLAN for voice traffic, entering the switchport voice and switchport priority extend
interface configuration commands has no effect.
When a connected device uses the same MAC address to request an IP address for the access VLAN
and then an IP address for the voice VLAN, only the access VLAN is assigned an IP address.
• When you enter a maximum secure address value for an interface, and the new value is greater than
the previous value, the new value overwrites the previously configured value. If the new value is less
than the previous value and the number of configured secure addresses on the interface exceeds the
new value, the command is rejected.
• The switch does not support port security aging of sticky secure MAC addresses.
Table 23-3 summarizes port security compatibility with other port-based features.
Table 23-3 Port Security Compatibility with Other Switch Features
Type of Port or Feature on Port Compatible with Port Security
DTP
1
port
2
1. DTP = Dynamic Trunking Protocol
2. A port configured with the switchport mode dynamic interface configuration command.
No
Trunk port Yes
Dynamic-access port
3
3. A VLAN Query Protocol (VQP) port configured with the switchport access vlan dynamic interface configuration command.
No
SPAN source port Yes
SPAN destination port No
EtherChannel No
Protected port Yes
IEEE 802.1x port Yes
Voice VLAN port
4
4. You must set the maximum allowed secure addresses on the port to two plus the maximum number of secure addresses
allowed on the access VLAN.
Yes
Flex Links Yes