SWITCH CONFIGURATION

SWITCH CONFIGURATION

1. Basic configuration of the switch

   • Configuration of initial switch parameters
     • Sequence of starting a switch
       • Finally, the boot loader locates and loads a software image of the IOS operating system into memory and delegates control of the switch to IOS.
       • The boot loader starts the flash file system on the system board.
       • The boot loader performs initialization of the low level CPU.
       • Next, the switch loads the boot loader software
       • First, the switch loads a self-diagnostic program
     • Recovery after a system crash
       • The boot loader provides access to the switch if the operating system can not be used due to the lack of system files or their damage.
     • LED indicators of the switches
       • You can use the switch LEDs to quickly control switch activity and performance
     • Preparation for basic management of a switch
       • To access remote administration of a switch, it must be configured with an IP address and a subnet mask.
     • Configuration of access to the basic administration of a switch with IPv4
       • An IPv4 address and a subnet mask are configured in the switch management SVI from the VLAN interface configuration mode.
   • Configuring ports of a switch
     • Duplex communication
       • Increase effective bandwidth by allowing both ends of a connection to transmit and receive data simultaneously
     • Configuration of switch ports in the physical layer
       • They can be configured manually with specific parameters of duplex and speed.
     • Auto-MDIX
       • The interface automatically detects the type of cable connection required (direct or crossover) and configures the connection according to that information.
     • Verification of the configuration of ports of a switch
       • The show interfaces command is another frequently used command that displays statistical and status information about the network interfaces of the switch
     • Problems of the network access layer
       • The output of the show interfaces command can be used to detect frequent media problems.
     • Troubleshooting the network access layer
       • The cables are damaged, the configuration changes, and new devices that require configuration changes are connected to the switch.

2. Switch security

   • Secure remote access
     • Operation of SSH
       • It is a protocol that provides a secure (encrypted) management connection to a remote device.
     • SSH configuration
       • Step 1: Verify compatibility with SSH
       • Step 2: Configure the IP domain
       • Step 3: Generate RSA key pairs
   • Switch ports security
     • Ports in disabling status due to errors
       • When a port is disabled due to errors, it is effectively deactivated, and traffic is not sent or received on that port.
     • Secure ports without using
       • A simple method that many administrators use to contribute to network security against unauthorized access is to disable all unused switch ports.
     • Port security: operation
       • Limit the number of valid MAC addresses allowed on the port. Access to the MAC addresses of legitimate devices is allowed, while other MAC addresses are rejected
     • Port security: verification
       • Check port security
       • Check the security parameters of the port