Lectures notes for 2010 - KTH

When are routes sent?
Solicited response: Send a response when a request is received
Unsolicited response:
• If a metric for a route changes, then (trigger) send update,
else send all or part of the table every 30 seconds.
• If a route has not been updated for 180 seconds (3 minutes = 6 update
cycles), then set metric to 16 and then after 60 seconds (1 minute)
delete route.
Metrics are in units of hops, thus this protocol leads to selection between routes
based on the minimum number of hops.
Summary of RIPv1 Timers:
• Periodic timer - regular updates random value [25..35] mean 30 s.
• Expiration timer - routes not updated within (180 s) expire
• Garbage collection timer - 120 s after expiring entries are GC’d
Maguire RIP v1 operation 7: 14 of 70
maguire@kth.se 2010.03.21 Internetworking/Internetteknik