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
