LAN Switching Technologies Flashcards

Which command enables PortFast on an individual switch interface?

Answer: spanning-tree portfast

The interface-level command 'spanning-tree portfast' enables PortFast, skipping the listening and learning STP states.

What is the maximum number of VLANs supported in the standard VLAN range (not extended)?

Answer: 1005

Standard VLANs range from 1 to 1005 on Cisco switches, with some reserved for specific uses.

A switch port is in err-disabled state. Which command restores it without manually shutting it down and bringing it back up?

Answer: errdisable recovery cause bpduguard

'errdisable recovery cause bpduguard' enables automatic recovery for ports shut down by BPDU Guard.

On a Cisco switch, which inter-VLAN routing method uses a single physical trunk link to a router with subinterfaces?

Answer: Router-on-a-stick

Router-on-a-stick uses one physical link with 802.1Q subinterfaces on the router, one per VLAN, for inter-VLAN routing.

Which spanning tree port state listens for BPDUs but neither learns MAC addresses nor forwards frames?

Answer: Listening

The Listening state processes BPDUs to determine topology but does not populate the MAC table or forward data.

What is the Cisco term for a per-VLAN implementation of Spanning Tree Protocol running on Cisco switches?

Answer: PVST+

Per-VLAN Spanning Tree Plus (PVST+) runs a separate STP instance for each VLAN, allowing per-VLAN root bridge selection.

Which command verifies the root bridge, port roles, and port states for VLAN 10 on a Cisco switch?

Answer: show spanning-tree vlan 10

'show spanning-tree vlan 10' displays STP details including the root bridge ID, local bridge ID, and each port's role and state.