Specifications

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Cisco 7100 Series VPN Router Installation and Configuration Guide
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Chapter 4 Performing a Basic Startup Configuration
Configuring a Router
Note To see a list of the configuration commands available to you, enter ? at the prompt or press the Help key
while in configuration mode.
Step 2 Specify the IP address. The following example uses an IP address of 10.1.1.10:
Router(config-if)# ip address 10.1.1.10 255.0.0.0
Step 3 Change the default settings or configure other features on the interface as needed.
The following example sets the external clock rate to 72 kbps:
Router(config-if)# clockrate 72000
Enter the clockrate ? command for a list of valid clock rates. If you enter a nonstandard clock rate (that
is, a rate not displayed by the clockrate ? command), the clock rate is rounded to the nearest value that
the hardware can support. To determine the value that the clock rate was rounded to, use the
show running-configuration command.
Set the external clock rate in bits-per-second if you are configuring a data communications equipment
(DCE) interface or you want to perform a loopback test. Skip this step if you are configuring a data
terminal equipment (DTE) interface; the interface automatically uses the external timing signal.
The T1 and E1 interfaces support both DTE and DCE mode, depending on the mode of the interface
cable attached to the port.
The DCE interface generates its own clock signal (TxC) and sends it to the remote DTE. The remote
DTE device returns the clock signal to the DCE. (See Table 4-2 for a list of commands used to change
the default settings.)
Note For more information on configuring interfaces, refer to the Cisco IOS Interface Configuration
Guide and the Cisco IOS Interface Command Reference publications. See “Related Documentation”
section on page xi for more information.
Step 4 Enable the interface.
Router(config-if)# no shutdown
Step 5 Press Ctrl-Z (hold down the Control key while you press Z) or enter end to exit configuration mode
and return to the EXEC command interpreter.
Step 6 Save the new configuration to NVRAM as follows:
Router# copy running-config startup-config
[OK]
(See the “Saving the Running Configuration to NVRAM” section on page 4-17. Also see the “Checking
the Interface Configurations” section on page 4-18 for examples of interface configurations.)
Configuring the T3 Interfaces
The Cisco 7120-T3 provides one and the Cisco 7140-2T3 provides two high-speed, synchronous serial
ports that support full-duplex operation at T3 (45-Mbps) speeds. The default settings and the commands
to change the defaults are listed in Table 4-3.