Maybe I'm missing something but how can HSRP (or first hop redundancy protocol) replace STP/Etherchannel? Even if 2 of the Catalyst switches in that topology were L3 gateways and ran HSRP you still need to deal with the L2 loop that exists.
On Wed, Mar 9, 2011 at 8:50 PM, [email protected] <[email protected]>wrote: > Well if yor timers are that bad for VOIP you can always use hsrp if you > don't want to use the etherchannel option. You can tune hsrp down to > milliseconds if you wanted to. Of course your distribution switches need to > support an enhanced IOS image > > Sent from my Verizon Wireless Phone > > ----- Reply message ----- > From: "Jay Taylor" <[email protected]> > Date: Wed, Mar 9, 2011 7:57 pm > Subject: [OSL | CCIE_RS] Rapid Spanning Tree convergence times > To: "marc abel" <[email protected]> > Cc: <[email protected]> > > > > Enable portfast on the host ports and you'll see a much quicker transition. > Just labbed this up and with portfast enabled I lost a single ping during > the failover. Without it enabled I lost 12. > > For the VoIP question - in production I'd recommend building with > Etherchannels just so STP never needs to converge. > > > On Wed, Mar 9, 2011 at 5:41 PM, marc abel <[email protected]> wrote: > > > I have 4 switches connected in a loop. > > > > Cat1-------------Cat2 > > | | > > | | > > Cat3----------Cat4 > > > > > > Cat 1 is the root, Cat 2 is the secondary root. All the switches are > > set to RPVSTP and I have confirmed that show spanning-tree shows RSTP > > as the protocol. Cat 4 shows it's interface to cat3 as it's root port > > and the interface to Cat3 as the Alternate. I have not tuned any > > timers. > > > > What should be the convergence time in this situation? > > > > If I run a ping from a host attached to Cat4 to a host attached to > > Cat1 and then I shut the Cat1-Cat3 interface (on the Cat1 side) it > > takes about 32 seconds before pings pick back up. I thought RSTP was > > supposed to converge in about 6 seconds? > > > > Another question, what is the fastest recovery time we can tune down > > to from RSTP? How do others tune this for VOIP? I know that I can get > > sub second convergence from OSPF but not all my switches have an > > appropriate image to run ospf. > > > > > > Thanks in advance. > > > > Marc > > _______________________________________________ > > For more information regarding industry leading CCIE Lab training, please > > visit www.ipexpert.com > > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > > > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
