Ah Bob, I was hoping for Op to read up on this with my original vague reply. ;)
Great explanation though. On 21 Jul 2014 05:56, "Bob McCouch" <[email protected]> wrote: > Priority 0 is still no guarantee in the real world. You could always have a > switch with a lower MAC address also configured for priority 0. Or it need > not even have a lower MAC if it is a switch where the MAC address > conservation feature "system extend-id" can be disabled (resulting in the > VLAN ID not being included as part of the priority value, thus winning over > a switch that does have MAC address conservation enabled). > > Also, root guard does not err-disable the port, it puts it into "Root > Inconsistent" state, which is effectively a blocking state. I mention this > because it hasn't technically stopped the rogue root from becoming the > "best" switch on the network, you've just stopped any other switch from > hearing about it. Hopefully. :-) > > STP -- the endless election. > > Best, > Bob McCouch > CCIE #38296 > HerdingPackets.net > > > On Sun, Jul 20, 2014 at 1:49 PM, Donald Robb <[email protected]> > wrote: > > > Yup in the CCIE there really isn’t any reason not to use priority 0 if > the > > lab wants a certain switch to be root. > > > > > > > > Cheers, > > > > Donald Robb > > > > Productive Networks / Network Consultant > > > > CCIE Written, CCIP, CCSP, CCDP, CCNP: R&S/Security, CCNA: DC/Voice, > JNCIP, > > SCP, MCSA 2012, VCA-DCV, CCA: XenApp 6, Security+, CCSE.R65, PACE > > > > > > > > From: L. Jankok [mailto:[email protected]] > > Sent: July 20, 2014 1:16 AM > > To: Donald Robb; 'Ahmed Haji Munye'; 'CC IE' > > Subject: Re: [OSL | CCIE_RS] Any definition why I can lower priority on > > Cat 3 all though I configured root guard on CA1? > > > > > > > > Exactly, that is why I only said priority 0 :) > > > > Op Sat, 19 Jul 2014 15:14:19 -0600 > > > > Donald Robb <[email protected] <mailto:[email protected]> > > > schreef: > > > > : Actually the job of root guard is to errdisable any links that > receives a > > > > : superior BPDU in order to protect the root. > > > > : Just a friendly reminder that it could lead to traffic loss or silo'd > > > > : switches in the real world :) > > > > : > > > > : Cheers, > > > > : Donald Robb > > > > : Productive Networks / Network Consultant > > > > : > > > > : CCIE Written, CCIP, CCSP, CCDP, CCNP: R&S/Security, CCNA: DC/Voice, > > JNCIP, > > > > : SCP, MCSA 2012, VCA-DCV, CCA: XenApp 6, Security+, CCSE.R65, PACE > > > > : > > > > : -----Original Message----- > > > > :From: [email protected] <mailto: > > [email protected]> > > > > : [mailto:[email protected]] On Behalf Of Ahmed Haji > > Munye > > > > : Sent: July 17, 2014 3:31 PM > > > > : To: CC IE > > > > : Subject: [OSL | CCIE_RS] Any definition why I can lower priority on > Cat 3 > > > > : all though I configured root guard on CA1? > > > > : > > > > : > > > > : > > > > : > > > > : Hi > > > > : > > > > : I am using the Proctor lab Switches and they are all 3560, and I can > > still > > > > : lower priority on cat 3 when I configured root guard on Cat 1. > > > > : > > > > : The job of the root guard is to prevent any other switches from > becoming > > > > : root bridge. > > > > : > > > > : Any definition why I can lower priority on Cat 3 all though I > configured > > > > : root guard on CA1? > > > > : > > > > : Regards > > > > : Ahmed > > > > : __________________________________________ _____ > > > > :Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos :: > > > > : > > > > : iPexpert on YouTube: www.youtube.com/ipexpertinc < > > http://www.youtube.com/ipexpertinc> > > > > : _______________________________________________ > > > > :Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos :: > > > > : > > > > : iPexpert on YouTube: www.youtube.com/ipexpertinc < > > http://www.youtube.com/ipexpertinc> > > > > _______________________________________________ > > Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos :: > > > > iPexpert on YouTube: www.youtube.com/ipexpertinc > > > _______________________________________________ > Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos :: > > iPexpert on YouTube: www.youtube.com/ipexpertinc _______________________________________________ Free CCIE R&S, Collaboration, Data Center, Wireless & Security Videos :: iPexpert on YouTube: www.youtube.com/ipexpertinc
