IEEE 802.1w Port information state machine requires a "ConfirmedRootMsg" to complete RSTP sync process. IEEE 802.1d , when the port is a root port specifies to transmit "the first four components of the designated priority vector" ( § 17.6 page 144 ) and not the "first four components of the port priority vector" as 802.1w require ( § 126.96.36.199 page 29 ).
In the topology of 4 DUTs, running 2 of them on 802.1D and other 2 on 802.1W. When there is topology change and Sync process is in progress, the new root port on DUT running with 802.1W expects the ConfirmedRootMsg, but as there is no such thing in 802.1D, sysc process never completes successfully.
[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...