Saturday, May 12, 2007

ROUTER Configuration (part: III end)

Cisco Basic Router

The basic component of cisco is :

1. Processor

2. Memory :
* Read only Memory (ROM) : This is like a rom at the pc, got standard program inside the rom and will run on booting process.
* Flash memory : Keeping Operation system of the Cisco called IOS
* Random access memory (RAM) : Using for buffering, storage and others.
* Non volatile RAM (NVRAM) : Keeping configuration from IOS when Cisco boot.

3. Interface :
The interface of cisco router is :

interface using format name dan number on IOS, The number started from zero (0). But the assigning the number belong to the type of the router. For the Cisco Router the interface modul is fixed:

For the Cisco Router 7500 series with versatile Interface processor, where is the modul got ethernet slot, the assigning system more specific and be carefully. Ethernet4/0/1 means port number 2 at 1st adapter in slot 4.

Console Console

Cisco Router have console port at behind the hadware. This port console be function for direct communication access into the Cisco router. The standard console port using serial asynchronous EIA/TIA-232, the others name is RS-232.

For the console port connector belong to the router type. For the Low end to middle router, using RJ45 connector, for the other Routers class using DB25 connector.

Auxiliary port

Cisco router have auxiliary port. port auxiliary using standard serial connection same with console port using serial asynchronous EIA/TIA-232 direct connection to Cisco router. Port auxiliary also for alternative access to the cisco router via modem, Administrator can used this serial when the network path from the router got problem.

Configuration File
Two type IOS configuration:
1. Existing configuration from the RAM
2. Startup configuration under NVRAM

We can change the configuration even the IOS active or running. The changes effected directly, but don't forget must save to NVRAM as startup once we changes the configure under running system.

Configure Cisco Router under PC

To configure Cisco Router from PC, need software communication called Emulation software terminal. This software function is sended the command into Cisco router. This software is has been installed included your Windows system.

Next step you have to setup the emulation software setting.

9600 baud
8 data bits
No parity
1 stop bit
No flow control

You can also connect to the router using telnet, but you must set the router IP first.

Router command mode:
This is some command of Cisco.

Started to setup new cisco:

To start configuration of Cisco, we must go under configure command.
The step to configure using the emulation software connected with console port of Cisco router is:

When the router boot up, Generally will be shown and asked you to confirm. Answer with : No

Would you like to enter the initial configuration dialog [yes] : no

Router prompt default is router> called user EXEC mode. Mode router>

router> We can changes display like dos command.


Under User EXEC mode can see all the command with type ?

router> ?

To let you know the syntax type:

Router> ?
Router> show ?
Router>show conf?

Access the mode must know the to enter the configure command:

1700> enable
password: ******
router #

For configure :

Router# configure terminal
Router (config) #

Once you changes the configure, save the configuration into NVRAM:

Router# copy running-config startup-config
Building configuration . . .

Save result:


The next step for configuration is:
• Global parameter configuration
• Security Configuration
• Fast ethernet interface configuration
• Serial interface configuration
• Dynamic routing configuration
• Command-line access to the router

Global parameter configuration:

To start router configuration, we must set configure with – enable :

Router> enable
Router #

Step to configure global parameter router :

Security configuration setting,


See the router prompt . . . has been changes with above

Serial INTERFACE setting

Dynamic routing parameter setting

COMMAND-LINE access configuration

To save all configuration :

1700# writ3e memory

To check configuration status:

stc# show interface ser0
Serial0 is up, line protocol is up
Hardware is PowerQUICC Serial
Description: leased line to headquarters
Interface is unnumbered. Using address of FastEthernet0 (
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation PPP, loopback not set, keepalive set (10 sec)
LCP Closed

make sure serial and protocol line is up.

We do the same setting in LTX side. The different is only on the router IP, we assign LTX IP :
Assign the ip for each modem before Router check with your provider.

LTX access internet must route to STC network, because direct access into Internet from STC network.

This is only basic to connect between different network, for security firewall must set into the router.


Original Template | by: Elque 2007 | Modify by : Jan Pieter Marbun (June 2007)