Cisco Catalyst 2960 Series, Configuration Manual

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Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and
feature information, see Bug Search Tool and the release notes for your platform and software release. To
find information about the features documented in this module, and to see a list of the releases in which each
feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support.
To access Cisco Feature Navigator, go to
http://www.cisco.com/go/cfn . An account on Cisco.com is not
required.
Information About Protected Ports
Protected Ports
Some applications require that no traffic be forwarded at Layer 2 between ports on the same switch so that
one neighbor does not see the traffic generated by another neighbor. In such an environment, the use of
protected ports ensures that there is no exchange of unicast, broadcast, or multicast traffic between these ports
on the switch.
Protected ports have these features:
• A protected port does not forward any traffic (unicast, multicast, or broadcast) to any other port that is
also a protected port. Data traffic cannot be forwarded between protected ports at Layer 2; only control
traffic, such as PIM packets, is forwarded because these packets are processed by the CPU and forwarded
in software. All data traffic passing between protected ports must be forwarded through a Layer 3 device.
• Forwarding behavior between a protected port and a nonprotected port proceeds as usual.
Because a switch stack represents a single logical switch, Layer 2 traffic is not forwarded between any protected
ports in the switch stack, whether they are on the same or different switches in the stack.
Default Protected Port Configuration
The default is to have no protected ports defined.
Protected Ports Guidelines
You can configure protected ports on a physical interface (for example, Gigabit Ethernet port 1) or an
EtherChannel group (for example, port-channel 5). When you enable protected ports for a port channel, it is
enabled for all ports in the port-channel group.
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
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Finding Feature Information