In STP for the first 20s (max-age) root bridge elections occur. In the same moment in which switch receives last BPDU which allow him to decide who is root bridge it also knows which are designated/non-designated ports. In this moment whole topology is converged. For all this swith have 20s. Why do we need additional 2*forward delay time(2*15s) to start forwarding packets ? Why do we need "listening phase" ? Why switch could not start forwarding/learning phase directly after topology 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...