| 4.2.4 |
This lab will help you become familiar
with the router show commands. The show commands are the most
important information gathering commands available for the router. The
show running-config (or "show run") is probably the single
most valuable command to help determine the current status of a router
because it displays the active configuration file running in RAM. The
show startup-config (or "show start") command displays the
backup configuration file that is stored in non-volatile or NVRAM.
This is the file that will be used to configure the router when it is
first started or rebooted with the "reload" command. All of
the detailed router interface settings are contained in this file.
|
| 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. This procedure will use your
router's Telnet client software and the remote router's Telnet
server software. |
| 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. |