CCNA 1 Module 10 Routing Fundamentals v3'1

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CCNA 1 Module 10 Routing Fundamentalsv3.1

• By
• Christina Morrissey

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Objectives

• Routed protocol
• IP routing protocols

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Routed Protocols Versus Routing Protocols
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Routed or Routable Protocols
This protocol handles the transmission of data
through Routers.
The Internet Protocol (IP) Novell's Internetwork
Packet Exchange (IPX). DECnet, AppleTalk, Banyan
VINES, and Xerox Network Systems (XNS).
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Connectionless Network Services
Packet switched processes
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Connection-Oriented Network Services
A connection is established between the sender
and the recipient before any data is transferred
known as circuit switched processes
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IP as a Routed Protocol

• IP is a connectionless, unreliable, best-effort
  delivery protocol.
• As information flows down the layers of the OSI
  model the data is processed at each layer.
• IP accepts whatever data is passed down to it
  from the upper layers.

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Routed Protocols

• As a packet travels through a network to its
  final destination, the layer 2 frame headers and
  trailers are removed and replaced at every layer
  3 device.
• This is because layer 2 frames are for local
  addressing.
• Layer 3 addresses are for end-to end addressing.

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Anatomy of an IP Packet

• Version
• IP header length (HLEN)
• Type-of-service
• Total length
• Identification
• Flags
• Fragment offset
• Time-to-live
• Protocol
• Header checksum
• Source address
• Destination address
• Options
• Padding
• Data

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Packet Propagation
Each router provides its services to support
upper-layer functions, Encapsulation and
de-encapsulation.
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Routing Protocols
Communicate between Routers and keep routing
Tables
Routing Information Protocol (RIP), Interior
Gateway Routing Protocol (IGRP), Open Shortest
Path First (OSPF), Border Gateway Protocol
(BGP), Enhanced IGRP (EIGRP).
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• ROUTING TABLE ENTRIES
• Protocol type
• Next-hop associations
• Routing metric
• Outbound interfaces

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• The following metrics are most commonly used by
  routing protocols
• Bandwidth
• Delay
• Load
• Reliability
• Hop count
• Ticks
• Cost

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Path Determination

• Path determination enables a router to compare
  the destination address to the available routes
  in its routing table, and to select the best
  path.

static routing or dynamic routing
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• The following process is used during path
  determination for every packet that is routed
     
• The destination address is obtained from the
  packet.
• The mask of the first entry in the routing table
  is applied to the destination address.
• The masked destination and the routing table
  entry are compared.
• If there is a match, the packet is forwarded to
  the port that is associated with that table
  entry.
• If there is not a match, the next entry in the
  table is checked.
• If the packet does not match any entries in the
  table, the router checks to see if a default
  route has been set.
• If a default route has been set, the packet is
  forwarded to the associated port. A default route
  is a route that is configured by the network
  administrator as the route to use if there are no
  matches in the routing table.
• If there is no default route, the packet is
  discarded. Usually a message is sent back to the
  sending device indicating that the destination
  was unreachable.

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Distance Vector

• Routers using distance-vector algorithms send all
  or part of their routing table entries to
  adjacent routers on a periodic basis. This
  happens even if there are no changes in the
  network. By receiving a routing update, a router
  can verify all the known routes and make changes
  to its routing table.
• Examples of distance-vector protocols
• Routing Information Protocol (RIP) - Hop Count
• Interior Gateway Routing Protocol (IGRP)
• Enhanced IGRP (EIGRP)

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LINK-STATE ROUTING PROTOCOL

• Link-state routing protocols respond quickly to
  network changes sending trigger updates only when
  a network change has occurred.
• And Link-state routing protocols send periodic
  updates, known as link-state refreshes, at longer
  time intervals, such as every 30 minutes.
• Examples of link-state protocols include Open
  Shortest Path First (OSPF) and Intermediate
  System-to-Intermediate System (IS-IS).

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IGP

• Routing Information Protocol (RIP) and (RIPv2)
• Interior Gateway Routing Protocol (IGRP)
• Enhanced Interior Gateway Routing Protocol
  (EIGRP)
• Open Shortest Path First (OSPF)
• Intermediate System-to-Intermediate System
  protocol (IS-IS)

EGP Border Gateway Protocol (BGP).
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• THE PROCESS OF ANDING

Determining the subnet network address