There are many variables that determine the exact time of reconvergence for spanning tree. Generally speaking, any traffic that goes across multiple switches will see a brief interruption if and when spanning tree root changes. The service interruption should generally be on the order of a minute or less.
Features such a RSTP and backbone fast can help but I don't believe "zero downtime" is possible since the spanning tree algorithm, even with tuning and ideal conditions, will take some finite time to converge to the new topology. Even RSTP, under ideal conditions, will generally take a few seconds to converge.
[toc:faq]The ProblemOn traditional switches whenever we have a trunk
interface we use the VLAN tag to demultiplex the VLANs. The switch needs
to determine which MAC Address table to look in for a forwarding
decision. To do this we require the switch to do...
[toc:faq]Introduction:Netdr is a tool available on a RSP720, Sup720 or
Sup32 that allows one to capture packets on the RP or SP inband. The
netdr command can be used to capture both Tx and Rx packets in the
software switching path. This is not a substitut...
IntroductionOSPF, being a link-state protocol, allows for every router
in the network to know of every link and OSPF speaker in the entire
network. From this picture each router independently runs the Shortest
Path First (SPF) algorithm to determine the b...