Greg Ketchum

Private VLANs When you configure private VLANS, the switch must be in VTP transparent mode. You Need a Primary VLAN and a Secondary VLAN There are two types of secondary VLANs: Isolated VLANs - Ports within an isolated VLAN cannot communicate with each other at the Layer 2 level. Community VLANs - Ports within a community VLAN can communicate with each other but cannot communicate with ports in other communities at the Layer 2 level. Private VLANs provide Layer 2 isolation between ports within the same private VLAN. Private-VLAN ports are access ports that are one of these types: Promiscuous - A promiscuous port belongs to the primary VLAN and can communicate with all interfaces, including the community and isolated host ports that belong to the secondary VLANs associated with the primary VLAN. Isolated - An isolated port is a host port that belongs to an isolated secondary VLAN. It has complete Layer 2 separation from other ports within the same private VLAN, except for the promiscuou

MSTP All switches need this: spanning-tree mst configuration instance 1 vlan 1-3 instance 2 vlan 4-6 instance 3 vlan 7-9 Root Needs this: spanning-tree mst 1-3 root primary

Cisco PVST+ 802.1d Root Bridge Elect Root Bridge -> Lowest Bridge ID Bridge ID -> Priority + MAC All ports on the Root Bridge are Designated ports and are in a Forwarding State. Root Bridge is the Reference Point for everyone else. Each switch in the network looks for the best path to the root bridge. Decision is made based on the path cost. If the path cost is the same Port ID breaks tie. All other ports towards the Root Bridge are put in Blocking/Alternate state. Path Cost Ethernet = 100 Fast Ethernet = 19 Gigabit = 4 10 Gigabit = 2 Port States - Convergence takes 50 seconds Disabled Blocking - 20 seconds Listening - 15 seconds Learning - 15 seconds Forwarding Network Changes BPDUs - Hello timer is sent every 2 seconds TCNs are sent up stream to each device notifing the switch of a change in the topology. TCAs are sent back down stream to acknowledge the changes. This is done untill the TCN reaches the Root Bridge. Rapid PVST+ 802.1w Root Bridge Elected the same way as 802.1d P