EtherChannel Flashcards
What is a flow in regards to EtherChannel?
A flow is a communication from a client to a server using a particular application
A single flow is _________________ onto a single port channel interface
Load Balanced
When a flow is established, the flow will go over multiple port channel interfaces or just one for the entirety of the flow?
Just one
True or False: Packets from the same flow are load balanced round robin style across all the interfaces in the port channel (EtherChannel)?
False. Flows go over a single port channel interface
Why do flows go over just one single port channel interface when they could go over multiple ones?
Because packets could arrive out of order and would break some applications if that were to happen
True or False: Any single flow receives the bandwidth of all the links in the port channel (EtherChannel) as a maximum?
False. The flow receives the bandwidth of a single port channel as it’s maximum bandwidth
Does EtherChannel also provide redundancy?
Yes. If a port channel interface goes down, the other port channel links will pick up the slack with redundancy
What is the starting rule of thumb recommendation for oversubscription from the access layer to the distribution layer?
20:1
This means if you had 20 PCs connected to access layer switch all at 1Gbps links you would require a single 1Gbps uplink from the access layer to the distribution layer to support those PCs and their needs
What is the primary benefit of EtherChannel?
It groups multiple physical interfaces into a single logical interface
Does Spanning Tree see the EtherChannel as multiple interfaces?
No, it recognized the EtherChannel as one interface
Traffic will be _________________ across all links in the EtherChannel
Load Balanced
What are the 3 terms you could also use in place of EtherChannel?
Port Channel
LAG (Link Aggregation)
Link Bundle
What are the 3 types of EtherChannel Protocols?
LACP (Link Aggregation Contol Protocol)
PAgP (Port Aggregation Protocol)
Static Ether Channel
Of the three available protocols for EtherChannel, which one is the most preffered?
LACP (Link Aggregation Control Protocol)
What do LACP and PAgP have in common?
Both sides of the link negotiate the port channel creation and maintenance
What is unique to Static EtherChannel that other two protocols don’t have?
The switches do not negotiate the creation and maintenance BUT the settings on both sides still must match for the Port Channel to come up
What protocol should you use if LACP isn’t availabe?
Static EtherChannel
What command do all three protocols use for configuration?
channel-group
What identical parameters must be in place to have the EtherChannel port come up?
Speed and Duplex
Access or Trunk Mode
Native VLAN and allowed VLANs on Trunks
Access VLAN on access ports
What two modes can LACP interfaces be set to?
Active or Passive
With LACP, if SW1s interface is set to Active and SW2s interface is set to Passive, will the port channel come up?
Yes
With LACP, if SW1s interface is set to Passive and SW2s interface is set to Passive, will the port channel come up?
No
With LACP, if SW1s interface is set to Active and SW2s interface is set to Active, will the port channel come up?
Yes
What is the recommended mode for LACP interfaces to be in on both sides of the link?
Active
What commands would be entered on both switches to create an EtherChannel group using LACP?
int range {range}
channel-group 1 mode active
int port-channel 1
switchport mode trunk
What two modes would interfaces be set at to configure PAgP?
Auto or Desirable
With PAgP, what mode(s) must both interfaces be set to for the EtherChannel to come up?
Desirable and Auto
OR
Desirable and Desirable
With PAgP, if both sides are set to Auto will the EtherChannel come up?
No
With PAgP, what mode is the most preferrable?
Desirable
What commands would you use to configure a PAgP EtherChannel group?
int range {range}
channel-group 1 mode desirable
int port-channel 1
switchport mode trunk
What commands would you use to configure a Static EtherChannel group?
int range {range}
channel-group 1 mode on
int port-channel 1
switchport mode trunk
What mode would Active or Passive be apart of?
LACP
What mode would Auto or Desirable be apart of?
PAgP
What mode would On be apart of?
Static EtherChannel
What command can be used to verify EtherChannel?
show etherchannel summary
Multi-Chassis EtherChannel is supported by which 3 technologies?
StackWise, VSS (Virtual Switching System) and vPC (Virtual Port Channel)
What model of switches can you find StackWise on?
Cat 3750, 3850 and the 9000 families
What model of switches can you find VSS on?
Cat 4500 and 6500 families
What model of switches can you find vPC on?
Nexus families
