Chap 5 - VLAN Trunks and Etherchannel Bundles Flashcards
What are the 4 roles in VTP architecture?
- Server
- Client
- Transparent
- Off
How many versions of VTP are there?
3
What is the difference between VTP versions 1 and 2 vs. 3?
- Versions 1 and 2 support VLANs 1 - 1005
- Version 3 supports VLANs 1 - 4094
- In VTP version 3 its not enough to be a VTP server, you also have to run the user exec command ‘vtp primary’
What version of VTP is the default?
Version 1
If a switch is running VTP version 3 what is the command to enable it as a server?
vtp primary’
What are the 3 main types of advertisements in VTP?
- Summary
- Subset
- Client Requests
What 2 times is a VTP Summary Advertisement sent, what 4 things does it include, and what does it not include?
- Occurs every 5 minutes or whenever a VLAN is added, removed, or changed
- Contains VTP version, domain, config revision number, and timestamp
- Does not contain VLAN information
What is a VTP Subset Advertisement?
- Occurs after a VLAN change
- Contains all relevant info for switches to make the VLAN change
What is a Client Request Advertisement?
- Occurs when a switch with a lower revision number joins the domain and sees advertisements with higher revision numbers than it has
- Client is asking for more detailed information.
What happens to the switchport configuration when the VLAN it is assigned to is removed?
The switchport moves to VLAN 1.
How often does DTP advertise itself?
Every 30 seconds.
What are the 3 modes to use when setting a switchport to trunk?
- Switchport mode trunk
- Dynamic Desirable
- Dynamic Auto
What is the IEEE standard for LACP?
802.3AD
What are the interfaces called that are part of an Etherchannel?
Member interfaces
What’s the downfall when configuring an Etherchannel statically?
There is no health integrity check.
What is the multicast MAC address used by PAgP?
0100:0CCC:CCCC
What is the protocol code used by PAgP?
0x0104
What is the multicast MAC address used by LACP?
0180:C200:0002.
What are the 2 negotiating modes used by PAgP?
Desirable and Auto
What are the 2 negotiating modes used by LACP?
Active and Passive
By default what operating mode do PAgP ports operate in?
Silent mode
What does PAgP silent mode do?
It allows formation of an Etherchannel even though the other side might not be PAgP
What does PAgP non-silent mode do?
Requires a port to receive a PAgP packet before adding it to an Etherchannel.
Which PAgP mode forms an Etherchannel faster - silent or non-silent?
Non-silent mode
How often does standard LACP send out LACP packets?
Every 30 seconds.
How often does LACP Fast send out packets?
Once every second.
What state will an LACP port channel be in when the minimum number of links is not met?
Not in Use
When configuring an LACP port channel for minumum number of links does that configuration need to be made on both sides?
No, but it is recommended.
What is a reason for configuring a minimum number of links in an Etherchannel?
To accommodate load-balancing hashes
In LACP where does the maximum number of interfaces need to be configured?
Only on the master switch but best practices say on both switches
How does the Master switch determine which member interfaces to make active when there are more than the maximum interfaces available?
By examining the LACP Port Priority. Lower priority is preferred. If there is a tie then lower interface number is preferred.
In LACP what determines which switch is the Master Switch?
The master switch is the switch with the lowest LACP System Priority.
How is the LACP System Priority configured?
SW1#config t
SW1(config)#lacp system-priority 1
What role does LACP Port Priority play?
It allows the Master LACP switch to determine which interfaces are active when there are more than the maximum number in the LACP port channel.
What 9 parameters must match in order for interfaces to be members of the same port channel?
- Load Interval
- Storm Control
- Speed
- Duplex
- Access/Trunk
- Native VLAN
- Allowed VLANs
- L2 / L3
- MTU
When troubleshooting an Etherchannel what 5 things should be checked?
- Between 2 devices only
- All member ports are up/up
- Both ends are statically configured with LACP/PAgP active on at least one side
- All member ports are configured exactly the same
- LACP or PAgP packets are being exchanged
How is Load Balancing done on an Etherchannel?
Based on a Hash which runs on various packet header fields.
What 5 things can the load balancing Hash be based on to Load Balance on an Etherchannel?
- MAC
- IP Address
- TCP/UDP
- IP Address and TCP/UDP
- Source or Destination
Is the Load Balancing method specific to a port channel or to the system?
The system.
Why should Etherchannels be configured in multiples of 2?
To make Load Balancing more effective.
Which protocol allows you to specify the maximum number of links in an Etherchannel?
LACP
Display the VTP status.
show vtp status
Display the VTP Revision Number.
show vtp status
Verify the status of a Port-channel.
show etherchannel summary
3 commands to view Etherchannel Neighbor info.
- R1#show etherchannel port
- R1#show lacp neighbor detail
- R1#show pagp neighbor
Display the LACP counters.
R1#show lacp counters
Clear the LACP counters.
R1#clear lacp counters
Display the PAgP counters.
R1#show pagp counters
Display whether LACP ports are operating in Fast Mode or Slow Mode.
show lacp internal
Display the LACP System Priority on a switch.
SW1#show lacp sys-id
Display the LACP interface priority.
show etherchannel port
Display the Load Balancing method being used by an Etherchannel.
show etherchannel load-balance
