Lab
2.3.2: Configure an Asynchronous Connection from a workstation to a
router with manual modem configuration
Objectives:
Make a successful asynchronous connection from a workstation to
a router with a modem attached.
Scenario:
You are working for the Atlanta Bread Company and would like to
setup out-of-band management on your router. You will properly
configure an asynchronous connection on your router and dialin from
a remote location.
Notes:
Lab Tasks:
Cable the equipment as shown in the diagram.
Log into the Atlanta Bread Company router and enter global
configuration mode.
Configure the following basic information into the router:
Configure the hostname Atlanta on the router.
Configure the router to prevent the lookup of misspelled
words.
What is the command to prevent the lookup of misspelled words?
Configure the enable password to be cisco.
Configure the FastEthernet 0/0 interface with the IP address
172.16.0.1/24.
Did the interface go up? If not then make it go up.
Configure EIGRP routing with AS# 100
Configure the line VTY 0 4 to request a login with the cisco
password.
Now it is time to configure the asynchronous connection! The
first step is to configure the serial interface for async
operation. The commands to configure the serial interface for
async operation are :
Atlanta(config)#interface serial 0/1
Atlanta(config-if)#physical-layer async
Note: The above interface is Serial 0 on the WIC-2A/S card. Refer
to your router's manual to see how the lines are counted for a
specific platform.
To find out the line number of the async interface, use the
show line
command. To see that the line has been created, check the
running-configuration of the router.
The next step will be to place a password on the dial-in line.
Continue using cisco as the password. The commands to do
this are:
Set the modem for both incoming and outgoing calls with the
following command:
Atlanta(config-line)#modem inout
Set the stopbits and allow all protocols to be passed to the
router through this line with the following commands:
Atlanta(config-line)#stopbits 1
Atlanta(config-line)#transport input all
The final step to configure the router is to configure a host to
IP mapping. This host to IP mapping must also include the port
number for the reverse telnet session. The command to do this is:
Atlanta(config)# ip host modem2 2002 172.16.0.1
Note: The name can be anything descriptive, here I just used
"modem2", and the port number is 2000 + the line number.
This modem is on line 2.
Write the configuration to memory.
To configure the modem to answer incoming calls you must
reverse telnet to the modem. A reverse telnet is a way to open a
terminal session on a modem through the router. It is used to
issue commands and save the configuration to the NVRAM of the
modem. The following commands can be used to reverse telnet to
the modem on line 2.
Atlanta# telnet modem2 or "telnet 172.16.0.1 2002"
Enter the "Cisco" password at the prompt.
Type "AT" and then press the Enter key. You are now in
the modem!
The modem should respond with "OK"
Type "AT&V" and then press the Enter key.
This command will display the contents of the modem's NVRAM and
current settings.
Type "AT&F" and then press the Enter key.
This command will reset the modem to default factory standards.
Type "ATS0=1" and then press the Enter key. This is a
'ZERO" not an 'O"
This command tells the modem to answer on the first ring.
On the Hayes Accura 56K modem, answer on the first ring, is the only
initialization string that we must program on the modem.
Type "AT&W" and then press the Enter key.
This command saves the configuration to the modem's NVRAM
Finally, press Control,Shift, 6 at the same time and then press
"X"
This will suspend your reverse telnet session.
Issue the following command to kill your reverse telnet session on
the router:
Atlanta# disconnect
From your desktop computer, install a modem and use
HyperTerminal to dial-in to the Atlanta router. If you placed the
modem into port #1 on the Adtran unit, you will be calling
555-6001. Once the modems connect you should see a password prompt
like the one below:
CONNECT 33600 V42bis
User Access Verification
Password:
Login to the router and issue a few commands. Issue the commands
"
who"
and "show line".
Record your findings below:
To disconnect from the router issue the following command:
Atlanta#exit
Congratulations! You now had a dialin connection to your router for
out-of-band management.
Note: On some Cisco 2600 series routers, if the router reboots, the
exec will fail on the first dialin attempt. You must press the Enter
key several times to get a password verification prompt and then
dialin again.