Chapter 5 Switch Configuation (Boot sequence (Finally, the boot loader…
Chapter 5 Switch Configuation
Close open ports not being used
Switch(config)# interface range type module/first-number – last-number
Secure MAC Address Types
Dynamic secure MAC addresses - MAC addresses that are dynamically learned and stored only in the address table. MAC addresses configured in this way are removed when the switch restarts or the port goes down.
Static secure MAC addresses - MAC addresses that are manually configured on a port by using the switchport port-security mac-address mac-address interface configuration mode command. MAC addresses configured in this way are stored in the address table and are added to the running configuration on the switch.
Sticky secure MAC addresses - MAC addresses that can be dynamically learned or manually configured, then stored in the address table and added to the running configuration until the switch restarts.
Disabling sticky learning converts sticky Mac addresses to dynamic mac address, removes them from running-conf.
no switchport port-security mac-address sticky
copy to startup-conf makes sticky mac address permanient and retained on reboot
Lost when switch reboots
Removed from running-conf if port security is disabled
unknown MAC addresses will generate a security violation
The MAC addresses of legitimate devices are allowed access, while other MAC addresses are denied.
Finally, the boot loader locates and loads a default IOS operating system software image into memory and gives control of the switch over to the IOS
The boot loader initializes the flash file system on the system board.
The boot loader performs low-level CPU initialization
The switch loads the boot loader software.
First, the switch loads a power-on self-test (POST) program stored in ROM.
The IOS operating system then initializes the interfaces using the Cisco IOS commands found in the startup-config file, which is stored in NVRAM.
Step 3. Reconnect the power cord to the switch and, within 15 seconds, press and hold down the Mode button while the System LED is still flashing green.
The boot loader can be accessed through a console connection.