What are the three switch functions?
Address learning, forward/filter decisions, and loop avoidance.
What does the "show mac address-table" do?
The "show mac address-table" shows the forward/filter table on the LAN switch.
What is the main purpose of Spanning Tree Protocol (STP) in a switched LAN?
The main purpose of STP is to prevent switching loops in a network with redundant switched paths.
What are the states of STP?
The blocking state is prevent the use of a looped path. A port in listening state prepares to forward data frames without populating the MAC address table. A port in learning state populates the MAC address table but doesn't forward data frames. A port in forwarding state sends and recieves all data frames on the bridged port. A port in the disabled state is virtually non-operational.
Be familiar with the command "showspanning-tree" and how to determine who the root bridge is.
What command will show you the forward/filter table?
show mac address-table.
If a destination MAC address is not in the forward/filter table, what will the switch do with the frame.
Flood the frame out all ports except the one it was revcieved on.
What are the three switch functions at Layer 2?
Address learning, forward/filtering, and loop avoidance.
What is used at layer 2 to prevent switching loops?
Spanning Tree Protocol (STP)
8022.1w is also called what?
Rapid Spanning Tree Protocol (RSTP)
When is STP considered to be converged?
When all ports are either in blocking or forwarding mode.
Switches break up ________ domains.
What is used to prevent switching loops in a network with redundant switch paths?
Which Cisco 802.1d extension stops BPDU from being transmitted out a port?
Which statement describes a spanning-tree network tat has converged?
Convergence occurs when all ports on bridges and switches have transitioned to eitehr the forwarding or blocking states. No data is forwarded until convergence is complete. Before data can be forwarded again, all devices must be updated.
When you connect to a switch port, at first the link lights are organge/amber, and then they turn green, indicating normal operation. If the light is blinking, you have a problem.
What commands will allow you toconfigure a Catalyst switch to be managed remotely?
You want to run the new 802.1w on your siwtches. Which of the following would enable this protocol?
In an improperly implemented redundant topology. If STP is not running on you switches and you connect them together with redundant links, you will have broadcast storms and multiple frame copies.
If you want to disable STP on a port connected to a server, which command would you use?
spanning-tree portfast - means that the port won't wait the usual 50 seconds to come up while STP is converging. (Maybe you have a server or other device connected to your network that you are sure won't create a switching loop if STP is disabled).
Layer two switching provides what?
Hardware based bridging (ASIC), Wire speed, low latency, and low cost.