187
Reauth period
This field displays how often a client has to re-enter his or her
username and password to stay connected to the port.
Quiet period
This field displays the period of the time the client has to wait before
the next re-authentication attempt.
Supp timeout
This field displays how long the Switch will wait before
communicating with the server.
Server timeout
This field displays how long the Switch will wait before
communicating with the client.
7.4.
Port Security
7.4.1.
Introduction
The Switch will learn the MAC address of the device directly connected to a particular port and
allow traffic through. We will ask the question: “How do we control who and how many can
connect to a switch port?” This is where port security can assist us. The Switch allow us to control
which devices can connect to a switch port or how many of them can connect to it (such as when
a hub or another switch is connected to the port).
Let’s say we have only one switch port left free and we need to connect five hosts to it. What can
we do? Connect a hub or switch to the free port! Connecting a switch or a hub to a port has
implications. It means that the network will have more traffic. If a switch or a hub is connected
by a user instead of an administrator, then there are chances that loops will be created. So, it is
best that number of hosts allowed to connect is restricted at the switch level. This can be done
using the “port-security limit” command. This command configures the maximum number of
MAC addresses that can source traffic through a port.
Port security can sets maximum number of MAC addresses allowed per interface. When the limit
is exceeded, incoming packets with new MAC addresses are dropped. It can be use MAC table
to check it. The static MAC addresses are included for the limit.
Note
: If you configure a port of the Switch from disabled to enabled, all of the MAC learned by
this port will be clear.
Default Settings
The port security on the Switch is disabled.
The Maximum MAC per port is 5.
The port state of the port security is disabled.
7.4.2.
CLI Configuration
Node
Command
Description
enable
show port-security
This command displays the current port security
configurations.
configure
port-security
(disable|enable)
This command enables / disables the global port security
function.
interface
port-security
This command enables / disables the port security
