My dear friend Micheline Murphy posted an excellent question on OSPF in a Hub and Spoke topology at the Cisco Learning Network. The scenario is a Hub and Spoke topology with two Hub routers that are ABRs belonging to area
CCDE – BGP Convergence
Introduction This post will look at the steps involved in BGP convergence and how it interacts with IGP to converge. Any network of scale will use route reflectors (RRs) so this post will focus on deployments with RRs. Networks running
Cisco Flex link
Introduction Flex link is a Cisco solution which replaces STP in certain network topologies. It works by detecting link down on a primary interface and then bringing up the backup interface that has been defined as backup. It is most
Detecting Network Failure
Introduction In todays networks, reliability is critical. Reliability needs to be high and convergence needs to be fast. There are several ways of detecting network failure but not all of them scale. This post takes a look at different methods
RSTP synchronization – behind the scenes
RSTP synchronization is not widely understood and often oversimplified. This post describes how it really works in detail to give you the full picture.
STP convergence – MST
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.