Lec2

• Routing Information Protocol(RIP)
• RIP - a dynamic routing protocol that uses hop count as a routing metric.
• RIP - a distance-vector routing protocol that has an AD value of 120
• RIP - Commonly used routing protocol in small to medium networks.
• RIP - Uses port number 520.
• RIP - Updates routing table every 30 seconds.
• Limitation of RIP

  • Auto Summarization

  • Loops

  • Distance Vector
• RIPv1 - uses classful routing.

  • No router authentication.

  • Uses broadcast on routing updates.
• RIPv1- No router authentication.
• RIPv1 - Uses broadcast on routing updates.
• RIPv2 - Support classless routing.
• RIPv2 - Adds authentication.
• RIPv2 - Uses multicast to send routing updates.
• RIP timers:

  • Update Timer
  • Invalid Timer
  • Hold Down Timer
  • Flush Time
• Update timer - The default timing for routing

  information being exchanged by the routers

  operating RIP is 30 seconds.
• Update timer - Using an Update

  timer, the routers exchange their routing table

  periodically.
• Invalid timer - If no update comes until 180

  seconds, then the destination router considers

  it invalid. In this scenario, the destination

  router mark hop counts as 16 for that router.
• Hold down timer - This is the time for which the

  router waits for a neighbor router to respond.

  If the router isn’t able to respond within a

  given time then it is declared dead. It is 180

  seconds by default.
• Flush time - It is the time after which the

  entry of the route will be flushed if it

  doesn’t respond within the flush time. It is 60

  seconds by default. This timer starts after the

  route has been declared invalid and after 60

  seconds i.e time will be 180 + 60 = 240

  seconds.