In a switched layer 2 network of all Cisco switches (2950/60s, 3550s etc) how can I determine what VLANs are no longer used?
What I mean by this is, VLAN 123 maybe defined on every switch, but if each switch has no access ports in this VLAN, then I would declare it no longer needed or used. However, the only way I can see to check in a given layer 2 environment would be to log into every switch and check if any ports are access ports for this VLAN (or read through the configs if they are to hand).
This seems very inefficient to me, especially in larger layer 2 networks. Does anyone know a faster, more efficient method?
[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...