This is Basic of Bridging. By that We are able to understand basics of Brigding. ALSO THIS SLIDE IS JUST FOR KNOWLEDGE.

1. BRIDGING

2. WHAT IS BRIDGING???
 Bridge is used to connect two or more different LAN networks.
 It is a device used to connect LAN cable segment together.
 Bridge operates at Data-Link Layer.
 It can connect on different architecture like Ethernet and Token-ring.

3. WHY DO WE USE BRIDGING???
 It provide Packet Filtering, meaning it only passes the packet that are allow on
destination Network

4. HOW IT WORKS???
 Bridge examine each packet as it enters through one of the port, it first check
MAC address of the sender and create a mapping between the port and the
sender MAC address. Then it looks the MAC address of Destination and
compare the list of all learned MAC addresses. If the address is in the list then
bridge look up the port number and forward the packet to the port where the
destination is connected. If the destination’s MAC address is not in the list, the
bridge blocks the data from passing.

5. CHARACTERISTICS OF BRIDGES
Routing Tables
 It contain one entry per station of network
to which bridge is connected.
 It is used to determine the network of
destination station of a received packet.
Filtering
 It is used by bridge to allow only those
packet destined to the remote network.
 Packets are filtered with respect to their
destination and multicast addresses.
Forwarding
The process of passing the Ticket from one
network to another.
Learning Algorithm
The process by which the bridge learns how
to reach stations on the internetwork.

6. TYPES OF BRIDGING
 Transparent Bridging
 Translational Bridging
 Source-route Bridging
 Local Bridging
 Remote Bridging

7. TRANSPARENT BRIDGING
 Also called learning bridges.
 Build a table of MAC addresses as frames arrive.
 Ethernet networks use transparent bridge.
Duties of transparent bridge
 Filtering Frames
 Forwarding
 Blocking

8. TRANSLATIONAL BRIDGING
 Useful to connect segments running at different speeds or using different
protocols such as token Ring and Ethernet networks.
 Translational Bridge can add or remove information and fields from frame as
needed.

9. SOURCE-ROUTE BRIDGING
 Used in Token Ring networks.
 Each station should determine the route to the destination when it wants to
send a frame and therefore include the route information in the header of
frame.
 Addresses of these bridges are included in the frame.
 Frame contains not only the source and destination address but also the
bridge addresses.

10. LOCAL BRIDGING
 MAC-layer Bridge
 Provides packet filtering and repeating services for the network segments of
the same type.
 Simplest type of Bridge because it has no need for packet filtering or
buffering.
 This Bridge simply propagates the incoming packets to the appropriate ports
or discard them.

11. REMOTE BRIDGING
 Connects network segments at different locations, using WAN link such as
MODEM or Leased line. The difference in speed between Local and wide area
links.
 Remote Bridge uses internal buffer to store the data received from LAN while
it is waiting for transmission to the remote site.

12. ADVANTAGES OF BRIDGING
 It is simple and significant.
 It prevents unnecessary traffic from crossing onto network.
 It helps to isolate the busy network to not-so-busy network.

13. DISADVANTAGES OF BRIDGING
 It is slower than HUB & repeater because they examine each frame’s source
and destination addresses.
 Bridge provide no protection against Broadcasting.
 Bridge cant make decision about routes through the Network.
 Expensive

14. WIRELESS AND WIRED BRIDGING
Wired Bridging
 Work on Layer 2 in OSI Model
 Only know about MAC Address
Wireless Bridging (Wireless Access
Point)
 Work on Layer 3 in OSI Model
 Know about IP address, Subnet
Mask, Routing etc.

15. THANK YOU…