Well you guys are right. I've always dealt with switches that have been etherchannelled to another switch so I never really dealt with switches that are single linked like that. I just don't know the reason why anybody wouldn't etherchannel their switches together. Hey I guess you live and you learn!
> Date: Wed, 9 Mar 2011 20:28:21 -0600 > Subject: Re: [OSL | CCIE_RS] Rapid Spanning Tree convergence times > From: [email protected] > To: [email protected] > CC: [email protected]; [email protected] > > Right because in my situation one of the links to the cores is going > to be in blocking state. I don't see any way around that. > > On Wed, Mar 9, 2011 at 8:25 PM, Jay Taylor <[email protected]> wrote: > > Even with HSRP and sub-second hellos you could lose pings depending on how > > STP needed to converge. > > > > On Wed, Mar 9, 2011 at 9:24 PM, Michael Smith <[email protected]> wrote: > >> > >> 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
