1. 資訊網路專題 Router & Practice
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2. Router Basics
Computers have four basic components: a CPU, memory, interfaces, and a bus.
A router also has these components
Router can also be called a computer
However, it is a special purpose computer that is dedicated to routing
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3. Router Components
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4. Internal Configuration Components of a Router
RAM/DRAM
NVRAM -- nonvolatile RAM
Flash -- erasable, re-programmable ROM
ROM
Interface
Include console port
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5. RAM for working Storage
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6. NVRAM NVRAM -- NonVolatile RAM
stores a router’s backup/startup configuration file
content remains when you power down or restart.
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7. Flash Erasable, re-programmable ROM
Holds the operating system image and microcode
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8. ROM Contains power-on diagnostics a bootstrap program, and
operating system software
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9. Interface
Network connection through which packets enter and exit a router
It can be on the motherboard or on a separate interface module
Also contains console & Aux ports
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10. Router Internal Components (an example)
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11. What does Router Look Like? (Cisco 2600)
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12. What does Router Look Like? (2600)
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13. What does Router Look Like? (2600)
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14. Computer Console Connection
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15. Connecting PC to Console Port - 1
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16. Connecting PC to Console Port - 1
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17. Router Serial WAN Connectors
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18. DCE Serial Connections
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19. Modem Connection to Aux Port
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20. WAN Router Connection
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21. Router Configuration
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22. Router Startup
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23. Startup Sequence
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24. Configuring a Router You can configure a router from
a virtual (remote) terminal
a modem connection
a console terminal
a network TFTP server
which allows you to maintain and store configuration information at a central site
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25. How to Access the CLI (or Router Configuration Sources)
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26. User & Privileged Modes
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27. User & Privileged Modes
User mode
Typical tasks include those that check the router status. In this mode, router configuration changes are not allowed.
Privileged mode
Typical tasks include those that change the router configuration.
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29. A lot more commands ….
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31. Show Configuration
show running-config (write term, for IOS 10.3 & earlier)
show startup-config (show config, for IOS 10.3 & earlier)
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32. show interface
displays configurable parameters and real-time statistics related to router interfaces 
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33. Router Modes
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34. Router Configuration Modes
Global
Interface
Routing Protocol mode
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36. Router Identification Configuration
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37. Password Configuration
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39. Routing Protocol Configuration
Router> enable Router# config t Router(config)# router igrp 100 (or router rip) Router(config-router)# network x.x.x (or net x.x.x.0, for all connected networks)
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Router(config-router)#network
Router(config-router)#network
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41. IP address configuration
Router> Router> enable Router# config t Router(config)# interface serial 0 (or int s0) Router(config-if)# ip address Router(config-if)# no shutdown (or no shut)
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42. Basic Networking Testing
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43. telnet
Can use the following commands, too
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44. If telnet fails
If Telnet to one router can occur, but failure to another router occurs, it is likely that specific addressing, naming, or access permission problems caused the Telnet failure.
It is possible that the problem exists on this router or on the router that failed as a Telnet target. In this case, the next step is to try ping
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45. ping
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46. Extended Ping
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47. traceroute
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48. show ip route
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49. show interface Test both physical & data link layer connection
show interface serial 0 (show int s 0)
show interface ether 0
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50. 解讀 show interface
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