ccna voice 640-641 pdf

ccna voice 640-641 pdf.This only works if the sticky option is enabled, as discussed next. .restrict: Enables the switch to generate security violation alerts. .shutdown: causes the switch to generate security violation alerts and disables the interface; the only way to re-enable the interface at this point is to use the commandno shutdowno If not specified, this is the default violation mode. When an interface is disabled due to a security violation, you can reset it using the configuration mode command errdisablerecoverycausepsecure-violation.In the above code listing, the last two commands determine how the switch learns the MAC address on the interface. The first command specifies the MAC addresses that can be associated with the interface, which statically specifies the devices that can be attached to the port; the second command uses the sticky feature to allow the switch to dynamically learn the MAC addresses associated with the interface and convert these dynamic entries to static entries. The maximum number of MAC addresses learned is not to exceed the maximum number of addresses configured for the interface. After you save the configuration (copyrunning-config startup-config) and reboot the switch, the addresses learned in a sticky manner become static secure addresses. Basically, sticky learning eliminates the need for you to configure the MAC address associated with the interface.If a MAC address is not statically specified and sticky learning is not enabled, dynamic learning will be used. Dynamic learning is similar to sticky learning in that the switch dynamically learns the MAC addresses until the maximum number specified is reached; however, unlike sticky learning, these addresses are not saved: the MAC addresses associated with the interface are relearned when the switch reboots or the interface is reset.Sticky and dynamic learning allow the switch to dynamically learn MAC addresses until the maximum number allowed is reached. With dynamic learning, the learned MAC addresses are not saved to the running configuration; with sticky learning, the learned MAC addresses are saved to the running configuration as a configuration command. This is the most efficient way to learn the MAC addresses connected to the switch. Static configuration MAC addresses are typically used for network devices, such as servers and routers. You can use a combination of static and sticky or static and dynamic, but the switch will not be informed of more than the configured maximum number of MAC addresses (the default is l) o11.5.2 Verifying Port SecurityTo verify the port security configuration, use the command show port-security interfaceoswitch# showport-security interface faO/2 Port Security : Enabled Port status : SecureUp Violation mode : Restrict Maximum MAC Addresses : 1 Total MAC Addresses : 1 Configured MAC Addresses : 1 Aging time : 0 mins Aging type : Absolute SecureStatic address aging : Disabled Security Violation count : 0In this example, port security is enabled, the violation mode is reset, the maximum number of MAC addresses that can be associated with the port is 1, and a MAC address is statically configured for the port. As you can see from the end of the above output, no security violations have occurred on the port.Be sure to familiarize yourself with the command showport-securityinterfaceo if this command shows a Port Security value of Disabled, you will need to use the command switchportport-security on the interface to enable port security. Also, be sure to be able to determine the number of MAC addresses configured (allowed). You can also use the command showrunning-config to verify the port security configuration of the switch interface.