Switches can be operated:
- Using CLI.
- Provide web interface (user can connect to the web server running in switch).
- Switches can be controlled and operated using network management software.
- Some switches from the 2960 family have 48 UTP ports (10/100/100) which means they can negotiate the use of cabling
- Switch’s physical connectors are interfaces or ports.
- The interface has type and number.
- interface type can be Ethernet, FastEthernet, Gigabit Ethernet, and so on.
- Naming interfaces: some switches use x/y or x/y/z port numbering methods.
- Cisco has an OS, IOS Internetwork Operating System
- CLI can be accessed by the console, telnet, and SSH
- Telnet and ssh use the IP network
- The console is a physical port built for accessing the CLI by laptop or PC
Accessing switch using console connection
- Contains three things: console cable, serial port on PC, and console port on switch
- The serial port has 9 pins (called DB-9) and its rectangular D-shell connector
- Rollover cable has pinouts and they are ordered as follows: 1 to 8, 2 to 7, 3 to 6, 4 to 5, 5 to 4, 6 to 3, 7 to 2, 8 to 1
- After the cable is plugged in, we need a software that will be used as a way to access CLI
- Terminal emulator software must be installed
- It treats all data as text, accepts the text typed by the user and sends it over the console cable to the switch
Accessing the CLI with Telnet and SSH
- Traffic flows through the IP network and not through a console cable.
- Telnet uses telnet client and telnet server concept
- Telnet client is the user that enters commands and sends them to switch
- Telnet server accepts commands and replies back to the user
- Telnet uses port 23
- Sends all data as plain text (not encrypted)
- SSH uses TCP, port 22
User and Enable Modes
- User EXEC – exec means switch executes a command
- User mode
- Enable or privileged mode
- Cisco IOS stores configuration commands in a configuration file
Three ways to remove startup configuration files
- write erase
- erase startup-config
- erase nvram
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