1> Yes, we can not disable stp on switch, by default the switch will be configured by pvst, you can change it to mst, the switch must be configured one of the two choices.
2> BPDUfilter enable command enable the filter function on the interface, filter out the BPDU packet,the purpose is a)in order to avoid the STP re-calculating. bï¼to save system resource consumption. c) to avoid the new device has the higher priority then grap the root-bridge from the original network.
1.) On a per-VLAN basis, the STP is disabled by saying no spanning-tree vlan N. Regarding disabling the STP on a port, there are two different forms of doing it. The first is the PortFast feature, i.e. declaring the port as an edge port by the command spanning-tree portfast. This actually isn't disabling STP at all. It just allows the port to transition immediately from Blocking (or Discarding) to Forwarding. However, the STP is still fully active on that port - it still sends and receives BPDUs, and if a BPDU is indeed received on a PortFast port, the PortFast feature is deactivated until the port is disconnected and connected again.
The second way to disable STP on a port is the BPDU Filter - read further.
2.) The BPDU Filter feature prevents a port from sending and optionally from receving updates. Its behavior is different depending on how the feature is activated.
If the feature is activated in global configuration mode using the spanning-tree portfast bpdufilter default command, then the feature is automatically activated on all PortFast-enabled ports. In this case, after port is connected, it sends 11 BPDUs in usual intervals. If no BPDU is received during this time or anytime after it, the port will stop sending BPDUs. If a BPDU is received on such a port, the Filter feature is deactivated for that port and the port becomes a normal STP port - it again starts sending and receiving BPDUs in a usual way.
If the BPDU Filter feature is activated directly on a port using the command spanning-tree bpdufilter enable, the port will never send or receive BPDUs and will remain completely unblocked under all circumstances. This is the way to disable STP on a port.
It was mentioned in Cisco Networking Academy CCNP3 curricula, and you can also trivially verify it by sniffing a switchport that has the BPDU Filter functionality enabled in global configuration mode.
There is no special theory behind this. The port simply sends a couple of BPDUs to possibly elicit a STP response from the other switch if there is any. The count of 11 BPDUs was probably chosen to span the entire max_age period where the port on the second switch can be blocked and therefore unresponsive to BPDUs.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...