Port Security on Cisco Switches

Port Security: 1900 Series Switches

1900 Series Switch

1900Switch(config-if)#port secure	Interface will become secure
1900Switch(config-if)#port secure max-mac-count 1	Only one MAC address will be allowed in the MAC table for this interface

2900 Series Switch

2900Switch(config)#int fa0/1
2900Switch(config-if)#port security
2900Switch(config-if)#port security max-mac-count 1	Only one MAC address will be allowed for this interface
2900Switch(config-if)#port security action shutdown	Port will shut down if violation occurs

2950 Series Switch

2950Switch(config)#int fa 0/1
2950Switch(config-if)#switchport port-security
2950Switch(config-if)#switchport port-security mac-address sticky	Interface converts all MAC addresses to sticky secure addressesonly the MAC address learned first will now be accepted on this port
2950Switch(config-if)#switchport port-security maximum 1	Only one MAC address will be allowed for this interface
2950Switch(config-if)#switchport port-security violation shutdown	Port will shut down if violation occurs

Resetting Switch Configuration

Resetting Switch Configuration

1900 Series Switch

1900switch#delete vtp	Removes VLAN Trunking Protocol (VTP) information
1900switch#delete nvram	Resets switch back to factory defaults
1900switch>en
1900switch#reload	Restarts the switch

2900/2950 Series Switch

switch#delete flash:vlan.dat	Removes VLAN database from Flash memory
Delete filename [vlan.dat]?	Press Enter
Delete flash:vlan.dat? [confirm]	Reconfirm by pressing Enter
Switch#erase startup-config	Erases file from NVRAM
Switch#reload	Restarts the switch

Configuration Example: EIGRP

Configuration Example: EIGRP

Figure A shows the network topology for the configuration that follows, which shows how to configure EIGRP using the commands covered in this chapter.

Figure 10-1. Network Topology for EIGRP Configuration

Note:

The host name, password, and interfaces have all been configured as per the configuration example in configuring a router section, "Configuration Example: Basic Router Configuration"

Boston Router

Boston>en
Boston#config t
Boston(config)#router eigrp 100	Enables EIGRP routing
Boston(config-router)#no auto-summary	Disables auto summarization
Boston(config-router)#eigrp log-neighbor-changes	Changes with neighbors will be displayed
Boston(config-router)#network 172.16.0.0	Advertises directly connected networks (classful address only)
Boston(config-router)#exit
Boston(config)#exit
Boston#copy run start

Buffalo Router

Buffalo>en
Buffalo#config t
Buffalo(config)#router eigrp 100	Enables EIGRP routing
Buffalo(config-router)#no auto-summary	Disables auto summarization
Buffalo(config-router)#eigrp log-neighbor-changes	Changes with neighbors will be displayed
Buffalo(config-router)#network 172.16.0.0	Advertises directly connected networks (classful address only)
Buffalo(config-router)#Ctrl+Z	Exits back to privileged mode
Buffalo#copy run start

Bangor Router

Bangor>en
Bangor#config t
Bangor(config)#router eigrp 100	Enables EIGRP routing
Bangor(config-router)#no auto-summary	Disables auto summarization
Bangor(config-router)#eigrp log-neighbor-changes	Changes with neighbors will be displayed
Bangor(config-router)#network 172.16.0.0	Advertises directly connected networks (classful address only)
Bangor(config-router)#Ctrl+Z	Exits back to privileged mode
Bangor#copy run start

Troubleshooting EIGRP

Troubleshooting EIGRP

Router#debug eigrp fsm	Displays events/actions related to the DUAL FSM
Router#debug eigrp packet	Displays events/actions related to EIGRP packets
Router#debug eigrp neighbor	Displays events/actions related to EIGRP neighbors

Verifying EIGRP

Verifying EIGRP

Router#show ip eigrp neighbors	Displays a neighbor table
Router#show ip eigrp neighbors detail	Displays a detailed neighbor table
Router#show ip eigrp interfaces	Displays information for each interface
Router#show ip eigrp int s 0/0	Displays information for a specific interface
Router#show ip eigrp int 100	Displays information for interfaces running process 100
Router#show ip eigrp topology	Displays the topology table. This command will show you where your feasible successors are
Router#show ip eigrp traffic	Displays the number and type of packets sent and received