Any chance of just doubling your links for each path? That would only require 2 extra pairs of fiber to each IDF rather than uplinking each switch. But then again, that 1 ping missed with RSTP was with default timers and I'm sure you could trim that down.
On Wed, Mar 9, 2011 at 9:32 PM, Michael Smith <[email protected]> wrote: > 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
