Chapter 2) Implementing Data Center Switching Protocols Flashcards
Describe the function of Spanning Tree edge ports.
Edge ports in spanning tree connect directly to end hosts. These ports can be either an access port or trunk port, and immediately transition to the forwarding state.
Describe the function of Spanning Tree network ports.
Network ports are normally connected only to switches or bridges. Bridge assurance is enabled only on network ports.
Describe the function of Spanning tree normal ports.
Normal ports can be connected to either hosts, switches, or bridges. These ports function as normal spanning tree ports.
What is the default spanning tree port type?
The default spanning tree interface is a normal port.
What is the function of the STP Bridge Assurance extension?
Spanning tree Bridge Assurance is one of those features that help prevent bridging loops in Layer 2 networks. When a BPDU is not received on an interface for a certain period of time, the port is disabled until it receives BDPUs again.
What is the function of the STP BPDU Guard extension?
This extension disables ports that receive a BPDU frame; it is useful for edge ports that should never be connected to another switch.
What is the function of the STP BPDU Filtering extension?
This extension prevents the switch from sending or even receiving BPDUs on a specified edge port.
What is the function of the STP Loop Guard extension?
This extension protects against network interfaces that malfunction. Loop Guard is useful only in switched networks where devices are connected by point-to-point links.
What is the function of the STP Root Guard extension?
This extension prevents a port from becoming a root port or a blocked port.
What is the default mode of STP for Cisco Nexus Switches?
Rapid PVST+
When do designated and root ports generate a TC (Topology Change)?
When the interface fails to receive 3 consecutive BPDUs, or when the max age timer expires.
What is the role and value of the TC While timer?
The TC While timer is equivalent to the hello interval + 1 second. While the TC While timer is running, the interface continues to set the TC flag on all BPDUs sent on that port.
What are the 4 Rapid PVST+ and MST port states?
Blocking: The switch LAN port does not participate in frame forwarding.
Learning: The switch LAN port prepares to participate in frame forwarding.
Forwarding: The switch LAN port forwards frames.
Disabled: The switch LAN port does not participate in STP and does not forward frames.
What the SPT short & high path-costs for a 10 Mbps link?
Short Path: 100
Long Path: 2,000,000
What the SPT short & high path-costs for a 100 Mbps link?
Short Path: 19
Long Path: 200,000