Flashcards in Chapter 11 - Supplement - Sheet1 Deck (40):
Benefits of layer 2 switching
Hardware-based bridging (ASIC), Wire speed, low latency, low cost
Application-specific integrated circuits. Switches make decisions based on ASIC chips (hardware) instead of software, like how bridges operate
Limitations of Layer 2 Switching
Switches don't break up broadcast domains, only collision domains
Three functions of layer 2 switching
Address learning, forward/filter decisions, loop avoidance
Switches build a forward/filter table of MAC addresses from the source field of packets sent to them.
Two version of the IEEE Spanning Tree Protocol
5 problems that can affect data as it traverses network cable
Delay, Dropped Packets, Error, Jitter, Out-of-order delivery
Belongs to and carries the traffic of only one VLAN
Carries multiple VLANs at a time
100Mbps or 1000Mbps point-to-point link between two switches, between a switch and a router, or between a switch and a server.
Max VLANS trunk links can carry traffic for
Two VLAN identification methods
VLAN ID method. Inter-Switch Link - Encapsulates the data frame with its own header (that has a VLAN ID) and a CRC. Proprietary to Cisco. Fast Ethernet and Gigabit Ethernet only
VLAN ID method. Inserts a field into the frame to ID the VLAN.
VLAN Trunking Protocol. Allows for management of VLANs throughout the network via a server or central switch
Default VTP mode for switches
Server, client, transparent
Power over ethernet
PoE IEE standard
POE with more power
PoE Plus IEEE standard
AKA SPAN (Switch Port Analyzer). Allows you to simulate a port on a switch from another point on the switch, which anables traffic sniffing of data going out a specific port
Spanning tree protocol.
Main purpose of STP
Prevent switching lops in a network with redundant switched ports
States of STP
Blocking, Listening, Learning, Forwarding, Disabled
Blocking State STP
Preent the use of looped paths
Listening State STP
Prepared to forward data frames without populating the MAC address table
Learning State STP
Populates the MAC address table but doesn't forward data frames
Forwarding State STP
Sends and received all data frames on a bridged port
Disabled State STP
VLANs break up ________ domains in a Layer 2 switched network.
Switches, by default, only break up ________ domains.
What does trunking provide?
Allows you to send information about many or all VLANs through the same link.
You need to power a device such as an access point or IP phone. What protocol can provide power to these devices over an Ethernet cable?
You plug a host into a switch port and the host receives an IP address but the user can’t get to the services it needs. What is probably the problem?
VLAN port membership could be wrong
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 port on which it was received
What are the three switch functions at Layer 2?
Address learning, filtering, and loop avoidance
If a frame is received on a switch port and the source MAC address is not in the forward/filter table, what will the switch do?
It will add the source MAC address to the forward/filter table
What is used at Layer 2 to prevent switching loops?
Spanning tree protocol.