Why is the RIP expiration timer value six times that of the periodic timer value?

Question

wht i meant was why is the other timer in exact multiple of 6...guess lots of ppl missing this point..

Answer 1

Looks like you already had 2 answers, but one is referring to IPX RIP and doesn't answer the question and the other answer is nonsense.

So the default RIP update timer is 30 seconds. Every 30 seconds the router blasts out its routing table to all of its directly connected neighbors. Then you have a holddown timer, during holddown, any routing information about a worse (or equivalent) hop count path is suppressed (held down). That is, RIP will not re-learn a route during this holddown period of 180 seconds. This allows time for "bad" routes to be removed from the routing table. In RIP, the default holddown is 3 times the update timer, or 180 seconds.

Then you have the invalid timer, after which the route is declared invalid, and this is also 180 seconds. Finally, you have the flush timer, this is the amount of time after which a route is dropped (flushed) out of the routing table. For RIP, the default flush timer is 240 seconds. If you haven't heard from a router in 240 seconds, you flush all of the routes you learned from it.

So in a nutshell, here are the default RIP timers:
Update: 30 sec
Holddown: 180 sec
Invalid: 180 sec
Flush: 240 sec

These defaults are generally left alone and are stable in most cases. The flush timer is the longest because it must be greater than the invalid timer, because if it's less then the holddown period cannot properly expire and this would result in a NEW route being accepted before the holddown elapsed.

Answer 2

Routing Information Protocol (RIP) uses Tick counts to make the best routing in a IPX envrionment. Tick count is an expected delay 1/18 of a second

Answer 3

because if the timer value was one-sixth to the negative of six for the six periodic signals it sends. It wouldn't be a multiple of six that the six expirations would take place in six different areas.

Answer 4

not sure, but You can check out this site to verify your public IP address: mysourceip.com