Inter-networking allows computers on different networks to communicate via gateways. Routers and bridges connect different network segments and allow communication between computers on different segments. Routers use destination IP addresses to pass data packets between networks, while bridges maintain a table of addresses to reduce traffic by only forwarding packets with valid destinations. A subnet mask is used to determine if an IP address is local or remote, and routable addresses can be reached by anyone on the internet while non-routable addresses are reserved for internal networks.

1. More Networking…

2. Learning Outcomes
• Explain the meaning of the term inter-
networking.
• Define routers, bridges and gateways and
consider where and why they are used.
• Consider how a subnet mask is used to
identify the network identifier part of an IP
address.
• Distinguish between routable and non-
routable IP addresses.

3. Inter-Networking
• Internetworking is formed when computers
from one network communicate with
computers from other networks.
• These networks communicate via gateways
• An example of inter-networking is the
internet, which has now become important
and widely used in everyday life
Key Explain the meaning of the term inter-
Learning networking.
Point

4. Routers
• Routers and Bridges allow communication
between computers on different segments
• A Router is a device that receives packets
from a router or a host and uses the
destination IP address the packets contain
to pass them to another router or host

5. Bridges
• A bridge holds a table of addresses for
each connected machine.
• Data packets received from one segment
are only forwarded if they have a valid
destination address on the other segment.
• This helps to reduce overall traffic.

6. Gateways
• A device used to connect networks using
different protocols so that information can be
passed from one system to another
• Gateways are used to connect LANs through
the internet
• In order to do this, they must translate the
LANs frame into equivalent WAN frame, vice
versa. This is because the LANs uses a
protocol that is different from the protocols
used on the internet which is WAN.

7. IP Address
• The subnet mask is
used by the TCP/IP
protocol to determine
whether a host is on the
local subnet or on a
remote network.
• Which class are these
addresses?
a) 10.52.165.23
b) 192.168.17.3
c) 150.266.193.1
d) 1.1.1.1
e) 128.255.243.19

8. Routable vs. Non-Routable
• A routable IP address is one that can be
reached (or routed) by anyone on the
internet.
• A non routable IP address means internet
people can't reach you (reserved by the
business)
– class A reserved space 10.0.0.0/8
– class B reserved space 172.16.0.0/12
– class C reserved space 192.168.0.0/16

9. Your Task
• Using the iPad you need to make a video to
show your understanding of the learning
outcomes.
• Once finished sync to DropBox.
– Explain the meaning of the term inter-networking.
– Define routers, bridges and gateways and consider
where and why they are used.
– Consider how a subnet mask is used to identify the
network identifier part of an IP address.
– Distinguish between routable and non-routable IP
addresses.