Well I'm talking as far as the VOIP phones go. They obviously need a gateway and to not miss any pings you can always turn on HSRP. I'm not saying HSRP has anything to do with spanning tree. Just thinking about the fact of not losing any pings.
Date: Wed, 9 Mar 2011 21:05:04 -0500 Subject: Re: [OSL | CCIE_RS] Rapid Spanning Tree convergence times From: [email protected] To: [email protected] CC: [email protected]; [email protected] 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
