1. router component and memory? How its work Console access
G12-Term1-2017/2018
Unit 5 : Routing concept
What is router?
Why routing ?
router component and memory?
How its work
Console access
Time to live TTL
Loopback interface
T. Shaikhah Sulaiman
Dibba Alfujairah Secondary School

2. When source IP and destinations are different

3. Connect one network to another
What is router?
Connect network to gather
Responsible for delivery of packets across different network
Use routing table to determine best path to forward packet
It is an intelligent device and has OS
Acts as Gateway
It is in layer3(network layer)
Network 1
Connect one network to another
Network 2

5. What is router Do?

6. Router are computer
central processing unit (CPU)
• operating system (OS)
• memory and storage (RAM, ROM, NVRAM, Flash, hard drive)

7. Router Memory hard drive, flash memory,
Volatile memory is computer storage that only maintains its data while the device is powered.
Like RAM (random access memory)
NV or Non-volatile memory that is saved regardless if the power to the computer is on or off.  
hard drive, flash memory,
ROM

8. Router Memory

9. A packet is the unit of data that is routed between an origin and a destination on the Internet or any other packet-switched network.

10. Routing table
The routing table is a table which is a record of all the networks the computer knows about
If the router does not know about a network, it will pass the packet to the default gateway, which is another router.
The routing table also includes the interface to be used to forward packets for each known network (i.e., which cable to send the packet through).

12. router Interface

13. Console Access
In a real environment, network infrastructure devices are commonly accessed remotely using Secure Shell (SSH). This allows you to use the CLI to make changes to the device without physically walking up and connecting to it.
Console access is when you physically connect to a console.
This is really only required when initially configuring a device, or if remote access fails. This is the physical connection to the device. To do this, you connect a cable from your laptop to the device, such as a router, then open up terminal emulation software to start making changes.
Console access requires:
• Console cable - RJ-45-to-DB-9 serial cable or a USB serial cable
• Terminal emulation software - Tera Term, PuTTY, HyperTerminal

15. Mapping the internet
a time-to live (TTL) is a value in an Internet Protocol (IP) packet that tells a network router whether or not the packet has been in the network too long and should be thrown away.
The TTL is set in an eight-binary digit field in the packet header by the sending host. When forwarding an IP packet, routers are required to decrease the TTL by at least one. If a packet's TTL has reached zero, the router detecting it discards the packet and sends a message back to the sending host.

16. Loopback interface
The loopback interface is a logical interface internal to the router. It is not assigned to a physical port and can therefore never be connected to any other device.
The loopback interface is useful in testing and managing a Cisco IOS device because it ensures that at least one interface will always be available. For example, it can be used for testing purposes,