The output from my lab below was from 'debug ip rip database' and 'debug ip routing'.
Bob -- Sent from my iPhone, please excuse any typos. On Jan 20, 2012, at 1:15 PM, "[email protected]" <[email protected]> wrote: > Hello > > What is the output of debup ip rip ? > -----Original Message----- > From: Rostam Sohrab <[email protected]> > Sender: [email protected] > Date: Fri, 20 Jan 2012 09:31:35 > To: Bob McCouch<[email protected]> > Cc: [email protected]<[email protected]> > Subject: Re: [OSL | CCIE_RS] Correct Understanding the RIP timers! > > Thanks to Bob & Donald! > > Those were certainly superb explanations making the understanding pretty > clear for me! > > -RS > > > ________________________________ > From: Bob McCouch <[email protected]> > To: Rostam Sohrab <[email protected]> > Cc: "[email protected]" <[email protected]> > Sent: Friday, 20 January 2012 8:51 AM > Subject: Re: [OSL | CCIE_RS] Correct Understanding the RIP timers! > > > Best way to see this is to lab it up. I set up a very simple network with R1 > and R2 connected via ethernet. I advertised a loopback from R2 into RIP, and > then on R2 set the ethernet interface passive to stop routing updates without > giving IOS any hints by dropping the interface. Here's what happened: > > R1#sh ip ro | b Gate > Gateway of last resort is not set > > 10.0.0.0/24 is subnetted, 2 subnets > R 10.1.0.0 [120/1] via 10.1.124.2, 00:00:12, FastEthernet0/0 > C 10.1.124.0 is directly connected, FastEthernet0/0 > > R1#sh clock > 22:03:17.475 UTC Wed Jan 19 2011 > R1#!This is when I set Fa0/0 passive on R2 > > R1# > Jan 19 22:05:56.975: RIP-DB: invalidated route of 10.1.0.0/24 via 10.1.124.2 > Jan 19 22:05:56.979: RT: delete route to 10.1.0.0 via 10.1.124.2, rip metric > [120/1] > Jan 19 22:05:56.979: RT: no routes to 10.1.0.0, entering holddown > Jan 19 22:05:56.987: RIP-DB: Remove 10.1.0.0/24, (metric 4294967295) via > 10.1.124.2, FastEthernet0/0 > > R1#sh ip ro | b Gate > Gateway of last resort is not set > > 10.0.0.0/24 is subnetted, 2 subnets > R 10.1.0.0/24 is possibly down, > routing via 10.1.124.2, FastEthernet0/0 > C 10.1.124.0 is directly connected, FastEthernet0/0 > > R1# > Jan 19 22:06:56.991: RIP-DB: garbage collect 10.1.0.0/24 > Jan 19 22:06:56.995: RT: delete subnet route to 10.1.0.0/24 > > R1#sh ip ro | b Gate > Gateway of last resort is not set > > 10.0.0.0/24 is subnetted, 1 subnets > C 10.1.124.0 is directly connected, FastEthernet0/0 > > > So 3 minutes after the last received update, the route was marked invalid, > and 60 seconds after that the route was flushed. So all timers are running > concurrently, the update timer, the invalid/holddown timers, and the flush > timer. > > > Bob > > > On Thu, Jan 19, 2012 at 6:56 AM, Rostam Sohrab <[email protected]> wrote: > > >> >> I have a little confusion in the understanding of RIP timers. >> >> First the basics... >> >> update timer is 30 secs --> Invalid timers should be 3 times of update i.e >> 90secs but the default is 180secs --> Holddown timers should be 3 times of >> update i.e, 90secs but the default is 180secs --> Flush timer, default is >> 240 secs. >> >> Now there are three parts to my question... >> >> The first question might sound silly but for the sake of a clear >> understanding I'll write it. >> >> >> 1. Does the RIP updates timers work is series? i.e after one elapses the >> other starts? >> >> ex: once U-30sec is over --> Invalid starts and runs for 180 secs --> >> Holddown starts and runs for another 180secs --> And finally flush timer >> starts and runs for 240secs. >> >> Here the total time would be 30+180+180+240=630secs until a route is flushed >> out which is looking quite unreasonable! >> >> 2. Does the Invalid, Holddown & flush timers work is parallel? >> >> ex: once U-30sec is over -> Invalid, Holddown runs for 180secs along with >> the flushtimer which runs for 240secs? >> >> Here the total time would be 30+240=270secs until a route is flushed out >> which looks very much acceptable. >> >> >> 3. And why does the Invalid & Holddown timers run in parallel, if all they >> do? >> >> Because at the end of these two timers (IT & HDT) it would take another >> 60secs for flush timer to flush out the route, which means that all the >> timers IT/HDT/FT are kicking off at the same time immediately after update >> timer expires! >> >> I think I'm just complicating what is supposed to be a simple >> understanding!!! >> >> -RS >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> >> Are you a CCNP or CCIE and looking for a job? Check out >> www.PlatinumPlacement.com >> >> http://onlinestudylist.com/mailman/listinfo/ccie_rs >> > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com > > http://onlinestudylist.com/mailman/listinfo/ccie_rs _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
