I am working on a network with a massive vlan 'd network. They are running dot1q everywhere, even though all the kit appears to be cisco. All trunks are in native VLAN 1, and trunking is allover the place.
As dot1q is a MST, this should mean that any changes to active trunks, loss of trunks, or new vlans created would knock out the STP accross the network.
Cisco implements PVST even with dot1q. In other words, you have one instance of spanning-tree for each VLAN. If a trunk or link disappears somewhere, it can have an impact on spanning-tree but that may not knock out the network. For sure, SPT recalculation can occur.
[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...