Chapter 4: Router Components Labs:
4.2.4 | In this lab you will use the show cdp command. Cisco Discovery Protocol (CDP) discovers and shows information about directly connected Cisco devices (routers and switches). CDP is a Cisco proprietary protocol that runs at the data link layer (layer 2) of the OSI model. This allows devices that may be running different network layer 3 protocols such as IP or IPX to learn about each other. CDP begins automatically upon a device's system startup, however if you are using Cisco IOS Release 10.3 or newer version of IOS you must enable it on each of the device's interfaces by using the cdp enable command. Using the command show cdp interface you will gather information CDP uses for its advertisement and discovery frame transmission. Use show cdp neighbors and show cdp neighbors detail to display the CDP updates received on the local router.
4.3.5 | In this lab, you will use the show cdp command. Cisco Discovery Protocol (CDP) discovers and shows information about directly connected Cisco devices (routers and switches). CDP is a Cisco proprietary protocol that runs at the data link layer (layer 2) of the OSI model. This allows devices that may be running different network layer 3 protocols such as IP or IPX to learn about each other. CDP begins automatically upon a device's system startup, however if you are using Cisco IOS Release 10.3 or newer version of IOS you must enable it on each of the device's interfaces by using the cdp enable command. Using the command show cdp interface you will gather information CDP uses for its advertisement and discovery frame transmission. Use show cdp neighbors and show cdp neighbors detail to display the CDP updates received on the local router.
4.4.2 | In this lab, you will work with the telnet (remote terminal) utility to access routers remotely. You will telnet from your “local” router into another “remote” router in order to simulate being at the console on the remote router.
4.4.3 | In this lab you will use ICMP or Internet Control Message Protocol. ICMP will give you the ability to diagnose basic network connectivity. Using ping xxx.xxx.xxx.xxx will send an ICMP packet to the specified host and then wait for a reply packet from that host. You can ping the host name of a router but you must have a static host lookup table in the router or DNS server for name resolution to IP addresses.
4.4.4 | In this lab you will use the IOS traceroute command. The traceroute command uses ICMP packets and the error message generated by routers when the packet exceeds its Time To Live (TTL).
4.4.7 | This is very important in troubleshooting a network problem. The clear counters command resets the counters that are displayed when you issue the show interface command. By clearing the counters you get a clearer picture of the current status of the network.
4.5.1 | Through the use of show commands, you should be able to see which interfaces are up (using show interface), what devices the router is connected to (using show CDP neighbors) and how the user can get there (using show protocols). With the information received from the show commands, you should be able to remotely access the neighboring routers (using telnet) and through the use of troubleshooting commands (such as ping and trace) you should be able to see which devices are connected. Your final goal is to construct a logical topology drawing of the network by making use of all the above commands without referring to any diagrams ahead of time.