Lesson 5 Understanding Network Hardware

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Lesson 5 Understanding Network Hardware
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OVERVIEW

• Repeaters
• Hubs and concentrators
• Bridges
• Routers
• Switches
• Gateways
• Firewalls
• Short-haul modems

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REPEATER

• A repeater
• Extends the distance of a Network run.
• Takes a weak Network signal in on one side,
  boosts the signal, and sends it out its other
  side.
• Operates at the physical layer of the OSI
  Networking model.

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Repeater

• A repeater
• Is only used to connect the same type of media.
• Can segment one of its connections from the
  other.

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Repeater
Using repeaters to expand Network length
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HUBS AND CONCENTRATORS

• Hubs and concentrators are used to connect
  Network nodes to Network backbones.
• Nodes are connected to hubs in a physical star
  fashion, whether they are used for a star or ring
  topology Network.

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Hubs and concentrators

• Properties
• Hubs echo data from each port to other ports on
  the hub.
• They are automatically positioned.

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Hubs and concentrators

• Features
• Built-in management.
• Auto sensing of connection speeds.
• High-speed up-links connecting the hub to a
  backbone.
• Built-in bridging and routing functions .

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Bridges
A typical hub arrangement
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BRIDGES

• Built-in switching.
• Bridges connect two Network segments.
• They have the intelligence to pass traffic from
  one segment to another.

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Bridges

• Bridges that can span different Networking
  systems and media are also available.
• They operate at the data link layer of the OSI
  model.
• They address information about all parts of your
  Network.

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ROUTERS

• Routers operate at the network layer of the OSI
  Model.
• They are far more intelligent than bridges in
  sending incoming packets to their destination.

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Routers

• Routers can translate from any of the protocols
  at layers 1-3 to any other protocols at layers
  1-3.
• They can connect similar and dissimilar networks.

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Routers

• Routers become a node on a Network and have their
  own Network address.
• They can determine and use the shortest route to
  a location.
• They form the backbone of the Internet.

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Routers

• Programming routers
• Connect a terminal or PC to the RS-232C port
  and program the router in text mode.
• Use the Network-based software to program the
  router.

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Routers
Network using routers
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SWITCHES

• Switches can rapidly switch connections from one
  port to another.
• They are connection-oriented.

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Switches

• They dynamically switch among ports to create
  connections.
• All ports coming into a switch are not part of a
  single collision domain.

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Switches
Network using hubs and switches
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GATEWAYS

• Gateways are application-specific interfaces.
• They link the 7 layers of the OSI Model when they
  are dissimilar at any or all levels.
• They can translate from Ethernet to Token Ring.

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FIREWALLS

• A firewall sits between two Networks and enforces
  Network security policies.
• They generally sit between a company LAN and the
  Internet.

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Firewalls

• Types
• Network-based
• Application-based

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SHORT-HAUL MODEMS

• Short-haul modems
• Provide point-to-point connectivity between a
  workstation and another device.
• Enable you to connect two distant RS-232C
  devices to each other.

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Short-haul modems

• Short-haul modems
• Can be used when a computer needs terminal
  access to a remote device.
• Are preferred when the two devices often or
  always need to be connected.

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Short-haul modems
Short-haul modem connection
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SUMMARY

• Repeaters
• Hubs and concentrators
• Bridges
• Routers
• Programming routers
• Switches
• Gateways
• Firewalls
• Short-haul modems