Recently a posted a question to Twitter about connecting two Cisco Catalyst switches. One switch has already booted and has the following configuration: The other switch is connected to Gi1/0/48 and has just been powered on. It has no configuration
These are my study notes for CCDE based on “CCIE Routing and Switching v5.0 Official Cert Guide, Volume 1, Fifth Edition” and “Designing Cisco Network Service Architectures (ARCH) Foundation Learning Guide: (CCDP ARCH 642-874), Third Edition“, “INE – Understanding MSTP”
Introduction This post is inspired by a post at IEOC about Uplinkfast and TCN which can be found here. Before we get to those parts, let’s recap how Ethernet and STP work together. Spanning Tree The Spanning Tree Algorithm builds
RSTP synchronization is not widely understood and often oversimplified. This post describes how it really works in detail to give you the full picture.
I would like to bust a common myth. One that I’m probably guilty of preaching before as well. We all know that when portfast is enabled the port will bypass the listening and learning phase of STP. Portfast can be
Hi guys, I am going to be doing two lectures on spanning tree over at the Cisco Learning Network. The first one will be aimed for CCNA level plus and the second one will be aimed for CCNP level plus.
In the comments I received a wish to compare RPVST+ with MST. RPVST+ is Ciscos proprietary STP running one instance per VLAN over 802.1Q trunks. MST is an industry standard which can run multiple instances but not one per VLAN.
Someone asked the other day how fast STP converges depending on PVST+ or RPVST+ or MST is running. Usually the answer for PVST+ is 30-50 seconds and for RPVST+ it’s fast, maybe less than a second. I thought I would
To be a CCIE we need a good grasp of switching and STP. This post by Petr Lapukhov (again) is one of the best I’ve ever seen on STP. This post describes PVST+ in detail. Read it here.
Electing the root Only one switch can be the root bridge. From the start all switches announce themselves as the root, when a switch hears of a superior BPDU it stops announcing itself as the root and instead forwards the