Cisco 2524 - Router - EN User manual

CHAPTER
Configuring the Cisco 2524 and Cisco 2525 Routers 4-1
Configuring the Cisco 2524 and
Cisco 2525 Routers
4
This chapter describes how to configure the Cisco 2524 and Cisco 2525 routers and
contains the following sections:
•Booting the Router for the First Time
•Configuring the Router
•Specifying the Boot Method
•Checking the Configuration Settings
•Getting More Information
This chapter provides just enough information to get the router up and running. For
Cisco IOS Release 11.0 and earlier releases, refer to the Router Products Configuration
Guide for additional configuration information. For Cisco IOS Release 11.1 and later
releases, refer to the Configuration Fundamentals Configuration Guide.
Booting the Router for the First Time
Each time you power on the router, it goes through the following boot sequence:
1The router goes through power-on self-test diagnostics to verify basic operation of the
CPU, memory, and interfaces.
2The system bootstrap software (boot image) executes and searches for a valid Cisco IOS
image (router operating system software). The source of the Cisco IOS image (Flash
memory or a Trivial File Transfer Protocol [TFTP] server) is determined by the
configuration register setting. The factory-default setting for the configuration register
is 0x2102, which indicates that the router should attempt to load a Cisco IOS image
from Flash memory.

4-2 Cisco 2524 and Cisco 2525 Router User Guide
Configuring the Router
3If after five attempts a valid Cisco IOS image is not found in Flash memory, the router
reverts to boot ROM mode (which is used to install or upgrade a Cisco IOS image).
4If a valid Cisco IOS image is found, then the router searches for a valid configuration
file.
5If a valid configuration file is not found in NVRAM, the router runs the System
Configuration Dialog so you can configure it manually. For normal router operation,
there must be a valid Cisco IOS image in Flash memory and a configuration file in
NVRAM.
The first time you boot your router, you will need to configure the router interfaces and then
save the configuration to a file in NVRAM. Proceed to the next section, “Configuring the
Router,” for configuration instructions.
Configuring the Router
You can configure the router using one of the following procedures:
•Configuration mode—Recommended if you are familiar with Cisco IOS commands.
•AutoInstall—Recommended for automatic installation if another router running
Cisco IOS software is installed on the network. This configuration method must be set
up by someone with experience using Cisco IOS software.
•System Configuration Dialog—Recommended if you are not familiar with Cisco IOS
commands.
Use the procedure that best fits the needs of your network configuration and level of
Cisco IOS experience.
Timesaver Acquire the correct network addresses from your system administrator or
consult your network plan to determine correct addresses before you begin to configure the
router.

Configuring the Cisco 2524 and Cisco 2525 Routers 4-3
Configuring the Router
Using Configuration Mode
You can configure the router manually if you prefer not to use AutoInstall or the System
Configuration Dialog. Take the following steps to configure the router manually:
Step 1 Connect a console terminal following the instructions in the section “Connecting
the Console Terminal and Modem” in the chapter “Installing the Cisco 2524 and
Cisco 2525 Routers,” and then power ON the router.
Step 2 When you are prompted to enter the initial dialog, enter no to go into the normal
operating mode of the router:
Would you like to enter the initial dialog? [yes]: no
Step 3 After a few seconds you will see the user EXEC prompt (Router>). Enter the
enable command to enter enable mode. You can only make configuration changes
in enable mode.
Router> enable
The prompt changes to the privileged EXEC (enable) prompt:
Router#
Step 4 Enter the configure terminal command at the enable prompt to enter
configuration mode:
Router# configure terminal
You can now enter any changes you want to the configuration.
Step 5 Press Ctrl-Z to exit configuration mode.
To see the current operating configuration, enter the show running-config command at the
enable prompt:
Router# show running-config
To see the configuration in NVRAM, enter the show startup-config command at the enable
prompt:
Router# show startup-config

4-4 Cisco 2524 and Cisco 2525 Router User Guide
Configuring the Router
The results of the show running-config and show startup-config commands will be
different if you have made changes to the configuration but have not yet written them to
NVRAM.
To make your changes permanent, enter the copy running-config startup-config
command at the enable prompt:
Router# copy running-config startup-config
********
The router is now configured and will boot with the configuration you entered.
Using AutoInstall
The AutoInstall process is designed to configure the router automatically after connection
to your WAN. In order for AutoInstall to work properly, a Transmission Control
Protocol/Internet Protocol (TCP/IP) host on your network must be preconfigured to provide
the required configuration files. The TCP/IP host may exist anywhere on the network as
long as the following two conditions are maintained:
1The host must be on the remote side of the router’s synchronous serial connection to the
WA N .
2User Datagram Protocol (UDP) broadcasts to and from the router and the TCP/IP host
must be enabled.
This functionality is coordinated by your system administrator at the site where the TCP/IP
host is located. You should not attempt to use AutoInstall unless the required files have been
provided on the TCP/IP host. For Cisco IOS Release 11.0 and earlier releases, refer to the
publication Router Products Configuration Guide for additional information. For
Cisco IOS Release 11.1 and later releases, refer to the publication Configuration
Fundamentals Configuration Guide.
Note AutoInstall works on synchronous serial connections only. The 2-wire
switched 56-kbps DSU/CSU module operates on switched 56-kbps circuits only; therefore,
you cannot use it for AutoInstall.

Configuring the Cisco 2524 and Cisco 2525 Routers 4-5
Configuring the Router
Take the following steps to prepare your router for the AutoInstall process:
Step 1 Attach the WAN cable to the router.
Step 2 Turn ON power to the router.
The router will load the operating system image from Flash memory. If the remote
end of the WAN connection is connected and properly configured, the AutoInstall
process will begin.
If AutoInstall successfully completes, you can write the configuration data to the
router’s NVRAM. Perform the following step to complete this task.
Step 3 Enter the copy running-config startup-config command:
Router# copy running-config startup-config
Taking this step saves the configuration settings that the AutoInstall process
created in the router. If you do not do this, your configuration will be lost the next
time you reload the router.
Using the System Configuration Dialog
If you do not plan to use AutoInstall, make sure all the WAN cables are disconnected from
the router. This will prevent the router from attempting to the run the AutoInstall process.
The router will attempt to run AutoInstall whenever you power it on if there is a WAN
connection on both ends and the router does not have a configuration file stored in
NVRAM. It can take several minutes for the router to determine that AutoInstall is not set
up to a remote TCP/IP host.
If your router does not have a configuration (setup) file and you are not using AutoInstall,
the router will automatically start the setup command facility. An interactive dialog called
the System Configuration Dialog appears on the console screen. This dialog helps you
navigate through the configuration process by prompting you for the configuration
information necessary for the router to operate.
Many prompts in the System Configuration Dialog include default answers, which are
included in square brackets following the question. To accept a default answer, press
Return; otherwise, enter your response.
This section gives an example configuration using the System Configuration Dialog. When
you are configuring your router, respond as appropriate for your network.

4-6 Cisco 2524 and Cisco 2525 Router User Guide
Configuring the Router
At any time during the System Configuration Dialog, you can request help by typing a
question mark (?) at a prompt.
Before proceeding with the System Configuration Dialog, obtain from your system
administrator the node addresses and the number of bits in the subnet field (if applicable)
of the Ethernet and synchronous serial ports. For more information about Internet Protocol
(IP) addresses and subnets, refer to the publication Internetworking Technology Overview.
(See the section “Getting More Information” at the end of this chapter.)
Take the following steps to configure the router using the System Configuration Dialog:
Step 1 Connect a console terminal to the console connector on the rear panel of your
router, and turn ON power to the router. (For more information, refer to the section
“Connecting the Console Terminal and Modem” in the chapter “Installing the
Cisco 2524 and Cisco 2525 Routers.”)
Note The default parameters for the console port are 9600 baud, 8 data bits, no parity, and
2 stop bits.
Step 2 After about 30 seconds, information similar to the following is displayed on the
console screen.
Note The messages displayed vary, depending on the Cisco IOS release and feature set
you selected. The screen displays in this section are for reference only and may not exactly
reflect the screen displays on your console.
When you see this information, you have successfully booted your router:
System Bootstrap, Version X.X(XXXX) [XXXXX XX], RELEASE SOFTWARE
Copyright (c) 1986-1992 by Cisco Systems
2500 processor with 4096 Kbytes of main memory
Notice: NVRAM invalid, possibly due to write erase.
F3: 5797928+162396+258800 at 0x3000060

Configuring the Cisco 2524 and Cisco 2525 Routers 4-7
Configuring the Router
Restricted Rights Legend
Use, duplication, or disclosure by the Government is
subject to restrictions as set forth in subparagraph
(c) of the Commercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 and subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer
Software clause at DFARS sec. 252.227-7013.
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco Internetwork Operating System Software
IOS (tm) X000 Software (IGS-J-L), Version XX.X(XXXX) [XXXXX XXX]
Copyright (c) 1986-1996 by Cisco Systems, Inc.
Compiled Fri 20-Oct-95 16:02 by XXXXX
Image text-base: 0x03030FC0, data-base: 0x00001000
Cisco 252X (68030) processor (revision A) with 4092K/2048K bytes of
memory.
Processor board ID 00000000
Bridging software.
SuperLAT software copyright 1990 by Meridian Technology Corp).
X.25 software, Version X.X, NET2, BFE and GOSIP compliant.
TN3270 Emulation software (copyright 1994 by TGV Inc).
Basic Rate ISDN software, Version X.X.
1 Ethernet/IEEE 802.3 interface.
2 Serial network interfaces.
1 ISDN Basic Rate interface.
32K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash (Read ONLY)
Notice: NVRAM invalid, possibly due to write erase.
--- System Configuration Dialog ---
At any point you may enter a question mark '?' for help.
Refer to the 'Getting Started' Guide for additional help.
Use ctrl-c to abort configuration dialog at any prompt.
Default settings are in square brackets '[]'.
Would you like to enter the initial configuration dialog? [yes]:
Step 3 Press Return or enter yes to begin the configuration process.

4-8 Cisco 2524 and Cisco 2525 Router User Guide
Configuring the Router
Step 4 When the System Configuration Dialog asks whether you want to view the current
interface summary, press Return or enter yes:
First, would you like to see the current interface summary? [yes]:
Any interface listed with OK? value "NO" does not have a valid
configuration
Interface IP-Address OK? Method Status Protocol
Ethernet0 unassigned NO not set up down
BRI0 unassigned NO not set up up
Serial0 unassigned NO not set down down
Serial1 unassigned NO not set down down
Step 5 Configure the global parameters. Choose which protocols to support on the
Ethernet interface. For IP installations, you can press Return to accept the default
values (in brackets) for most of the questions. A typical configuration follows:
Configuring global parameters:
Enter host name [Router]:
Next, you are prompted to enter an enable secret password. There are two types of
privileged-level passwords:
•Enable secret password (a very secure, encrypted password)
•Enable password (a less secure, nonencrypted password)
The enable password is used when the enable secret password does not exist.
For maximum security, be sure the passwords are different. If you enter the same
password for both, the router will accept your entry, but will display a warning
message indicating that you should enter a different password.
Step 6 Enter an enable secret password:
The enable secret is a one-way cryptographic secret used
instead of the enable password when it exists.
Enter enable secret: pail
The enable password is used when there is no enable secret
and when using older software and some boot images.

Configuring the Cisco 2524 and Cisco 2525 Routers 4-9
Configuring the Router
Step 7 Enter the enable and virtual terminal passwords:
Enter enable password: shovel
Enter virtual terminal password: vterm1
Step 8 Press Return to accept Simple Network Management Protocol (SNMP)
management, or enter no to refuse it:
Configure SNMP Network Management? [yes]: no
Step 9 In the following example, the router is configured for AppleTalk, IP, and IPX.
Configure the appropriate protocols for your router:
Configure Vines? [no]:
Configure LAT? [no]:
Configure AppleTalk? [no]: yes
Multizone networks? [no]: yes
Configure DECnet? [no]:
Configure IP? [yes]:
Configure IGRP routing? [yes]:
Your IGRP autonomous system number [1]: 15
Configure CLNS? [no]:
Configure bridging? [no]:
Configure IPX? [no]: yes
Configure XNS? [no]:
Configure Apollo? [no]:
Step 10 Enter the ISDN BRI switch type for the router. The ISDN switch type appropriate
for the router depends on the ISDN provider’s equipment. Table 4-1 lists the ISDN
switch types.
Enter ISDN BRI Switch Type [none]: basic-5ess

4-10 Cisco 2524 and Cisco 2525 Router User Guide
Configuring the Router
Table 4-1 ISDN Switch Types
Configuring the ISDN BRI Interface
This section explains how to configure the ISDN BRI interface. If an ISDN BRI WAN
module is not installed in your router, skip this section and proceed with the next section,
“Configuring the Ethernet or Token Ring Interfaces.”
Country ISDN Switch Type Description
Australia basic-ts013 Australian TS013 switches
Europe basic-1tr6 German 1TR6 ISDN switches
basic-nwnet3 Norwegian NET3 ISDN switches (phase 1)
basic-net3 NET3 ISDN switches (UK and others)
vn2 French VN2 ISDN switches
vn3 French VN3 ISDN switches
Japan ntt Japanese NTT ISDN switches
North America basic-5ess AT&T basic rate switches
basic-dms100 NT DMS-100 basic rate switches
basic-ni1 National ISDN-1 switches
New Zealand basic-nznet3 New Zealand NET3 switches

Configuring the Cisco 2524 and Cisco 2525 Routers 4-11
Configuring the Router
The ISDN BRI interface is configured to allow connection to ISDN WANs. To configure
the ISDN BRI interface, respond as follows (using your addresses and subnet mask) to the
setup prompts, substituting the correct addresses and host names as appropriate:
Configuring interface BRI0:
Is this interface in use? [yes]
Configure IP on this interface? [yes]
IP address for this interface: 172.16.71.1
Number of bits in subnet field [0]: 8
lass B network is 172.16.0.0, 8 subnet bits; mask is
255.255.255.0
Configure AppleTalk on this interface? [no]: yes
Extended AppleTalk network? [no]: yes
AppleTalk starting cable range [0]: 1
AppleTalk ending cable range [1]: 2
AppleTalk zone name [myzone]:
AppleTalk additional zone name: otherzone
AppleTalk additional zone name:
Configure IPX on this interface? [no]: yes
IPX network number [1]: B000
Configuring the Ethernet or Token Ring Interfaces
Take the following steps to configure the Ethernet or Token Ring interface to allow
communication over a LAN. To configure the interface parameters, you need to know your
Ethernet or Token Ring interface network addresses. In this example, the system is being
configured for an Ethernet LAN using IP.
Step 1 Respond as follows (using your addresses and subnet mask) to the setup prompts,
substituting the correct addresses and host names as appropriate:
Configuring interface Ethernet0:
Is this interface in use? [yes]:
Configure IP on this interface? [yes]:
IP address for this interface: 172.16.72.1
Number of bits in subnet field [8]: 8
Class B network is 172.16.0.0, 8 subnet bits; mask is
255.255.255.0

4-12 Cisco 2524 and Cisco 2525 Router User Guide
Configuring the Router
Step 2 Enter yes if you will be using AppleTalk on the interface. Enter yes to configure
the router for extended AppleTalk networks, and then enter the cable range. Enter
the zone name, and any other additional zones that will be associated with your
local zone:
Configure AppleTalk on this interface? [no]: yes
Extended AppleTalk network? [no]: yes
AppleTalk starting cable range [0]: 3
AppleTalk ending cable range [1]: 3
AppleTalk zone name [myzone]:
AppleTalk additional zone name: otherzone
AppleTalk additional zone name:
Step 3 Determine if you are going to enable IPX on the interface. If so, enter yes and then
enter the unique IPX network number:
Configure IPX on this interface? [no]: yes
IPX network number [1]: B001
Configuring the Synchronous Serial Interfaces
The synchronous serial interfaces are configured to allow connection to WANs. Once the
Ethernet or Token Ting port on your router has been configured, take the following steps to
configure the synchronous serial interfaces:
Step 1 Press Return or enter yes to configure serial port 0:
Configuring interface Serial0:
Is this interface in use? [yes]:
Step 2 Determine which protocols you want on the synchronous serial interface and enter
the appropriate responses. In this example, the system is being configured for IP,
AppleTalk, and IPX:
Configure IP on this interface? [yes]:
Configure IP unnumbered on this interface? [no]:
IP address for this interface: 172.16.73.1
Number of bits in subnet field [8]:
Class B network is 172.16.0.0, 8 subnet bits; mask is
255.255.255.0
Configure AppleTalk on this interface? [no]: yes
Extended AppleTalk network? [yes]:
AppleTalk starting cable range [2]: 4

Configuring the Cisco 2524 and Cisco 2525 Routers 4-13
Configuring the Router
AppleTalk ending cable range [3]: 4
AppleTalk zone name [myzone]: ZZ Serial
AppleTalk additional zone name:
Configure IPX on this interface? [no]: yes
IPX network number [2]: B002
Step 3 Configure the second synchronous serial interface, for example, as follows:
Configuring interface Serial1:
Is this interface in use? [yes]:
Configure IP on this interface? [yes]:
Configure IP unnumbered on this interface? [no]:
IP address for this interface: 172.16.74.2
Number of bits in subnet field [8]:
Class B network is 172.16.0.0, 8 subnet bits; mask is
255.255.255.0
Configure AppleTalk on this interface? [no]: yes
AppleTalk starting cable range [3]: 5
AppleTalk ending cable range [4]: 5
AppleTalk zone name [myzone]: ZZ Serial
AppleTalk additional zone name:
Configure IPX on this interface? [no]: yes
IPX network number [3]: B003
Step 4 The configuration you enter is now displayed and you are asked if you want to use
the displayed configuration. If you enter no, you will lose the configuration
information you just entered and you can begin the configuration again. If you
enter yes, the configuration will be entered and saved in the startup configuration:
Use this configuration? [yes/no]: yes
Building configuration...
Use the enabled mode 'configure' command to modify this
configuration.
Press RETURN to get started!

4-14 Cisco 2524 and Cisco 2525 Router User Guide
Configuring the Router
Configuring ISDN
If you have an ISDN BRI WAN module, configure the BRI port for ISDN. This section
explains typical ISDN configurations for one or two B channels. In the examples that
follow, the BRI port is configured for IP routing, Challenge Handshake Authentication
Protocol (CHAP), and Point-to-Point Protocol (PPP) encapsulation.
Take the following steps to configure the router for a basic ISDN PPP connection on a
single B channel or two B channels, substituting the correct addresses and host names as
appropriate for your network:
Step 1 Enter enable mode:
Router> enable
password: enablepassword
Step 2 Enter the configure terminal command. Then enter the host name and password
that the router will use for CHAP caller identification:
Router# config term
Router (config)# username targetrouter password abc
Note The username and password must match the username and password already set on
the router to which the ISDN connection will be made. The username and password are
case sensitive.
Step 3 If you have not already done so, enter the isdn switch-type command to configure
the ISDN switch type:
router (config)# isdn switch-type switch-type
Refer to Table 4-1 earlier in this chapter for a list of ISDN switch types.

Configuring the Cisco 2524 and Cisco 2525 Routers 4-15
Configuring the Router
Step 4 Enter the BRI interface, encapsulation method (PPP), authentication type, target
router’s IP address and ISDN number to dial, and the dialer group number:
Router (config)# interface bri port_number
Router (config-if)# encapsulation ppp
Router (config-if)# ppp authentication chap
Router (config-if)# dialer map ip targetrouter_ipaddress
targetrouter_phonenumber
Router (config-if)# dialer-group groupnumber
Note Do not use periods or hyphens when you enter dialing numbers.
Step 5 Some ISDN switch types, such as Basic NI1 or DMS-100 switch service, require
you to configure a service profile identifier (SPID). Enter the SPID information as
follows, substituting the appropriate entries for your installation:
Router (config-if)# isdn spid1 SPID_no phone_number
Router (config-if)# isdn spid2 SPID_no phone_number
Step 6 To set up a second B channel for bandwidth on demand, enter the load-threshold
command to set the ISDN load threshold. The load threshold determines the
percentage of network loading at which the second ISDN B channel is triggered.
The value ranges from 1 to 255 (100 percent).
Router (config-if)# dialer load-threshold 128
In this example, the value of 128 means that when the first B channel reaches
50 percent of its bandwidth capacity (128 equals 50 percent of 255), the second B
channel will be activated to assist with the bandwidth load.
Step 7 Enter the access-list command to configure the ISDN line to come up whenever
IP packets are to be sent:
Router (config-if)# access-list access-list-number permit ip
sourcerouter-ipnetwork sourcerouter-subnetmask
targetrouter-ipnetwork targetrouter-subnetmask
Router (config)# dialer-list groupnumber list access-list-number

4-16 Cisco 2524 and Cisco 2525 Router User Guide
Configuring the Router
Step 8 Configure a static route to allow connectivity to the target router’s local network.
Enter the network number of the target router’s local IP network and subnet mask,
and the IP address of the target router’s BRI port.
Router (config)# ip route targetrouter_ipnetwork subnetmask
targetBRIport_ipaddress
Step 9 Enter the exit command to exit configuration mode.
Step 10 Enter the copy running-config startup-config command to save the
configuration to NVRAM.
Configuring Switched 56
This section explains how to configure the 2-wire switched 56-kbps and 4-wire 56/64-kbps
DSU/CSU WAN modules for switched 56-kbps circuit-switched service.
You can configure the 2-wire switched 56-kbps DSU/CSU WAN module for
switched 56-kbps service, but not Digital Data System ([DDS], which are leased or
dedicated lines). The 4-wire 56/64-kbps DSU/CSU WAN module is configured for DDS as
the factory default, but it can be configured for either switched 56/64-kbps service or DDS.
(See the next section, “Configuring DDS.”)
For Cisco IOS Release 11.0 and earlier releases, refer to the Router Products Command
Reference for more information about the commands in this section. For Cisco IOS
Release 11.1 and later releases, refer to the Configuration Fundamentals Command
Reference.
Take the following steps to configure the 2-wire switched 56-kbps and 4-wire 56/64-kbps
DSU/CSU WAN module for circuit-switched service, substituting the correct addresses and
host names as appropriate for your network:
Step 1 Enter enable mode:
Router> enable
password: enablepassword
Step 2 Enter configuration mode:
Router# config term
Router(config)#

Configuring the Cisco 2524 and Cisco 2525 Routers 4-17
Configuring the Router
Step 3 Assign an IP address to the serial port on the module:
Router(config)# interface serial port_number
Router(config-if)# ip address ipaddress subnetmask
Router(config-if)# no keepalive
Step 4 If you have a 2-wire switched 56-kbps WAN module, skip this step and proceed
to Step 5. If you have a 4-wire 56/64-kbps DSU/CSU WAN module, set the
network type to switched as follows:
Router(config-if)# service-module 56k network-type switched
Step 5 Set the carrier type, where carrier can be att, sprint, or other:
Router(config-if)# service-module 56k switched-carrier carrier
Step 6 Enter the dialer information:
Router(config-if)# dialer in-band
Router(config-if)# dialer string targetrouter_phonenumber
Router(config-if)# dialer-group groupnumber
Router(config-if)# exit
Router(config)# dialer-list groupnumber protocol protocol permit
Router(config)#
Step 7 Return to user EXEC mode:
Router(config)# exit
Router# exit
Router>
Configuring DDS
The 4-wire 56/64-kbps DSU/CSU WAN module is configured for DDS (which are leased
or dedicated lines) as the factory default, but it can be configured for either
switched 56/64-kbps service or DDS. The DDS configuration is described in this section.
To configure the 4-wire 56/64-kbps DSU/CSU WAN module for circuit-switched service,
follow the instructions in the previous section, “Configuring Switched 56.”
For Cisco IOS Release 11.0 and earlier releases, refer to the Router Products Command
Reference for more information about the commands in this section. For Cisco IOS
Release 11.1 and later releases, refer to the Configuration Fundamentals Command
Reference.

4-18 Cisco 2524 and Cisco 2525 Router User Guide
Configuring the Router
Take the following steps to configure the 4-wire 56/64-kbps DSU/CSU WAN module for
DDS, substituting the correct addresses and host names as appropriate for your network:
Step 1 Enter enable mode:
Router> enable
password: enablepassword
Step 2 Enter configuration mode:
Router# config term
Router(config)#
Step 3 Assign an IP address to the serial port on the module:
Router(config)# interface serial port_number
Router(config-if)# ip address ipaddress subnetmask
Router(config-if)# no keepalive
Step 4 Set the network type to DDS:
Router(config-if)# service-module 56k network-type dds
Step 5 Return to user EXEC mode:
Router(config-if)# exit
Router(config)# exit
Router# exit
Router>
Configuring the Fractional T1/T1 DSU/CSU WAN Module
This section describes how to configure the fractional T1/T1 DSU/CSU WAN module. This
module is configured for Extended Superframe Format (ESF) signal format, bipolar eight
zero substitution (B8ZS), and full bandwidth as the factory default. Depending on your
networking environment, you might need to change these settings.
For Cisco IOS Release 11.0 and earlier releases, refer to the Router Products Command
Reference for more information about the commands in this section. For Cisco IOS
Release 11.1 and later releases, refer to the Configuration Fundamentals Command
Reference.

Configuring the Cisco 2524 and Cisco 2525 Routers 4-19
Configuring the Router
Take the following steps to configure the fractional T1/T1 DSU/CSU WAN module for a
typical leased-line connection, substituting the correct addresses and host names as
appropriate for your network:
Step 1 Enter enable mode:
Router> enable
password: enablepassword
Step 2 Enter configuration mode:
Router# config term
Router(config)#
Step 3 Assign an IP address to the serial port on the module:
Router(config)# interface serial port_number
Router(config-if)# ip address ipaddress subnetmask
Router(config-if)# no keepalive
Step 4 Enter the framing type and line code type, substituting framing_type with sf
(Superframe) or esf (Extended Superframe)and linecode_type with ami (alternate
mark inversion) or b8zs (bipolar eight zero substitution):
Router(config-if)# service-module t1 framing framing_type
Router(config-if)# service-module t1 linecode linecode_type
Step 5 If you are using fractional T1 service, enter the time slot range and speed. In the
following example, the time slot range is from 1 to 20 and the speed is 64-kbps:
Router(config-if)# service-module t1 timeslots 1-20 speed 64
Step 6 Return to user EXEC mode:
Router(config-if)# exit
Router(config)# exit
Router# exit
Router>

4-20 Cisco 2524 and Cisco 2525 Router User Guide
Specifying the Boot Method
Specifying the Boot Method
You can enter multiple boot commands in the configuration in NVRAM to provide a
backup method for loading the Cisco IOS image onto the router. The router boots using the
first boot command that succeeds. If you enter multiple boot commands, the router executes
them in the order they are entered. There are two ways to load the Cisco IOS image: from
Flash memory or from a TFTP server on the network.
1Flash memory
Information stored in Flash memory is not vulnerable to network failures that might
occur when you load system software from servers. In the following example, replace
filename with the filename of the Cisco IOS image:
Router> enable
Password: enablepassword
Router# configure terminal
Router (config)# boot system flash filename
Router (config)# Ctrl-Z
Router# copy running-config startup-config
Building configuration ...
[OK]
Router# exit
Router>
2TFTP server
If Flash memory is not available, or if Flash memory does not contain a valid Cisco IOS
image, you can specify that system software be loaded from a TFTP server on your
network as a backup boot method for the router. In the following example, replace
filename with the filename of the Cisco IOS image, and replace ipaddress with the IP
address of the TFTP server:
Router> enable
Password: enablepassword
Router# configure terminal
Router (config)# boot system tftp filename ipaddress
Router (config)# Ctrl-Z
Router# copy running-config startup-config
Building configuration ...
[OK]
Router# exit
Router>