1. INTERNAL & EXTERNAL
OF ROUTERS

2. What is a Router ?
Router is a device which makes communication possible between two or more different networks present in different geographical locations.
To make communication possible between two or more different networks present in the same geographical location, what are the steps to be taken:
Answer : Configuring a Software Router or Implementing the CIDR concept

3. HYD CHE Is communication possible ? 10.0.0.1/8 S0 S1 10.0.0.2/8 E0
/24
HYD
LAN /24
CHE /8 S0 S1 /8

4. Is communication possible ?
The same networks present in different geographical locations cant communicate through a router because if Network ID of both the networks is same then the request will not go out of the router and it’ll keep on searching within the LAN.

5. Which Routers to buy ?
Many companies are manufacturing Router :
Cisco
Nortel
Multicom
Cyclades
Juniper
Dlink
Linksys
3Com
But Cisco is having monopoly in the market of Routers

6. Cisco’s Hierarchical Design Model
Cisco divided the Router into 3 Layers
Access Layer Router
Distribution Layer Router
Core Layer Router

7. Access Layer Router
Routers which are used by the Small Organization and are also known as Desktop or Company Layer Routers.
Router Series : 800, 1000, 1600, 1700, 2500
Cisco 1700
Cisco 1760
Cisco 800

8. Distribution Layer Router
Routers which are used by the ISPs and are also known as ISP Layer Routers
Router Series : 2600, 3200, 3600, 3700
Cisco 2600XM/2691
Cisco 3700
Cisco 3600

9. Core Layer Router
Routers which are used by the Global ISPs and are also known as Backbone Routers
Router Series : 6400, 7200, 7300, 7400, 7500, 7600, , 12000
Cisco 7000

10. Router Classification
Fixed Router are just like a branded PC where modification of interfaces is not possible
Access Layer Routers are example of Fixed Router except 1600 and 1700 series
Modular Router are just like a Assembled PC where modification of interfaces is possible
Distribution and Core Layer Routers example of Modular Router
FIXED ROUTER
MODULAR ROUTER

11. Example Modular Router

12. Model 2501 AUI Attachment Unit Interface E0 Serial Ports S0 and S1
Power Switch
Console
Con 0
Auxiliary
Aux 0
Power
Supply
This slide depicts the broad range of Cisco access router product portfolio.
With this announcement, Cisco is enhancing its access router portfolio to offer enterprise customers with a broadest range of routers to meet the needs of enterprise teleworkers, small offices, branch offices, regional offices, all the way to enterprise HQ.
This provides customers with the benefit of standardizing on a single operating environment which they are familiar with across all varying office sizes to simplify deployment, maintenance, and lowering support costs and training.
In the small office space, with the Cisco SOHO & 800 Series, Cisco has introduced new models such as the SOHO 71 which brings affordable multi-user access and Internet security for Small Businesses as well as new DSL models with an integrated 4 port hub.

13. Attachment Unit Interface
AUI pin configuration is 15 pin female.
It is known as Ethernet Port or LAN port or Default Gateway.
It is used for connecting LAN to the Router.
Transceiver is used for converting 8 wires to 15 wires. i.e. RJ45 to 15 pin converter.

14. Transceiver

15. Attachment Unit Interface
An IP address needs to be assigned to this interface and it should be in the same network as of the LAN. E0
/24
LAN /24
1.1
1.2
1.3
Straight Cable
Straight Cable

16. Attachment Unit Interface
/24
If you connect Router AUI to directly to PC NIC Card then You have to use Cross Cable
Cross Cable
1.1
LAN /24

17. Crimping of Twisted pair Cable
Straight cable
It is used between unlike device (dissimilar devices) e.g. Hub to PC, Switch to PC, Hub to Router 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

18. Crimping of Twisted pair Cable
Cross cable
It is used between like device (Similar devices) e.g. Hub to HUB, PC to PC, Switch to Switch, HUB to Switch, PC to Router 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

19. Crimping of Twisted pair Cable
Rollover Cable
It is used for connecting Router Console Port to PC Com Ports or Serial ports. 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

20. Serial Port
Serial pin configuration is 60 pin configuration female (i.e. 15 pins and 4 rows) and Smart Serial pin configuration is 26 pin configuration female.
It is known as WAN Port
It is used for connecting to Remote Locations
V.35 cable is having 60 pin configuration male at one end and on the other end 18 pin configuration male.

21. V.35 Cable

22. Console Port
It is known as Local Administrative Port
It is generally used for Initial Configuration, Password Recovery and Local Administration of the Router. It is RJ45 Port
IMP : It is the most delicate port on the Router. So make less use of the Console Port.

23. Console Connectivity

24. Console Connectivity
Connect a rollover cable to the router console port (RJ-45 connector).
Connect the other end of the rollover cable to the RJ-45 to DB-9 converter
Attach the female DB-9 converter to a PC Serial Port.
Open Emulation Software

25. DB9 Converter

26. Auxiliary Port
It is known as Remote Administrative Port.
Used for remote administration
Its an RJ-45 port
A console or a rollover cable is to be used.

27. Auxiliary Connectivity

28. 2601 Model Router

29. LAN interfaces - Ethernet
Brief Overview
WAN interfaces
Serial interface (S0, S1 etc) – 60 pin/26 pin(smart serial)
ISDN interface(BRI0 etc) – RJ45
LAN interfaces - Ethernet
AUI (Attachment Unit Interface) (E0)– 15 pin
10baseT – RJ45
Administration interfaces
Console – RJ45 - Local
Auxiliary – RJ45 - Remote

30. Internal Components
ROM
A bootstrap program is located here. It is same as the BIOS of the PC. Bootstrap program current version is 11.0
Flash
Internetwork Operating System (IOS) developed by Cisco is stored here. IOS is Command line interface.

31. Internal Components
NVRAM
Non volatile RAM, similar to Hard Disk
It is also known as Permanent Storage or Startup Configuration. Generally size of NVRAM is 32 KB.
RAM
It is also known as Temporary Storage or running Configuration. Minimum size of RAM is 2MB. The size of RAM is greater than NVRAM in the Router.
Processor
Motorola Processor 70 Mhz, RISC based processor
(Reduced Instruction Set Computer)

32. Internal Components

33. (verifies) the hardware ROM
Boot sequence
POST
Power on Self Test
(verifies) the hardware
ROM
Contact the ROM
Loads the Bootstrap Program
& Search where IOS is located
FLASH
IOS found in Flash
Loading IOS
NVRAM
Flash contacts the NVRAM
For Configuration File
RAM
NVRAM configuration copied into RAM