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Cisco Trunking Port Channel a.k.a. Ether Channel

Is there a best practice setup for which ports and should be trunked and which should be used for port channel (a.k.a ether channel).  I am a student and looking for generalized feedback.  

I have access to Cisco Packet tracer and or Dynamips and GNS3.  

Lets just say we have 6 Cisco (only) switches and there are 14 different VLANS.  The switches have 24 10/100/1000 copper ports and each switch has 2 fiber 10Gb/s ports.

Thank you,
R
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rotarypwr
Asked:
rotarypwr
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4 Solutions
 
Ernie BeekExpertCommented:
Trunks would be used if you want to have multiple VLANs traverse through a port (or etherchannel). For example for interconnecting switches when you want all of the VLANs to be reachable from both switches.

Etherchannels are used to combine multiple ports to get a higher bandwidth. So instead of connecting switches through one port (1Gb) you use a channel width, let's say, three ports hence getting a 3Gb throughput.
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Craig BeckCommented:
In Cisco speak, trunks refer to VLANs (as Ernie said).  Other vendors refer to trunks as bundled links (Cisco's EtherChannel).

For Cisco, use a trunk when you want to transport VLANs over a layer2 link.  Use EtherChannel when you want to combine more than one link to form a redundant or aggregated layer2 link.
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rotarypwrAuthor Commented:
I want to be able to have the trunks configured as well as the port channel, , should I use the two fiber ports for the trunks and the port channel or , should I use the Fiber for the trunks only and maybe 4 - 10/100/1000 copper ports for the port channel and run the trunks separately from the port channel ?

I am not looking for what trunks and port channels do or how to configure them, this much I know.  I am trying to figure out if they should be configured separately or on the same ports all together and if so, which ports should I use given the aforementioned equipment?  What does Cisco recommend?   Lets just assume that all ports are in use and we have a lot of LAN traffic.

TIA
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Craig BeckCommented:
Well this is where the confusion is - you will put the trunks 'inside' the port-channel.  The port-channel will be used to bundle the ports, then the bundle will be configured as a trunk to carry multiple VLANs.

This means that, in Cisco speak, you have to do them together or there's not much point in doing them.  There's absolutely no point in configuring a port-channel if it doesn't carry any traffic.

In a Cisco switch you'd do this:

interface range GigabitEthernet1/0/1 - 4
 switchport
 switchport mode access
 switchport access vlan 10
 channel-group 1 mode active
end

That will give you 4 interfaces in an etherchannel, carrying only VLAN 10 traffic.


Or, to carry a trunk including VLANs 10 - 20, you'd do this:

interface range GigabitEthernet1/0/1 - 4
 switchport
 switchport mode trunk
 switchport trunk allowed vlan 10-20
 channel-group 1 mode active
end
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Ernie BeekExpertCommented:
Let's put it this way:
An Etherchannel is a (virtual) interface (port-channel). A trunk is configured ON an interface. So it's not a matter of 'or'. You can configure a trunk on an Etherchannel just like on any other interface.
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Ernie BeekExpertCommented:
Aaand typing way too slow again I see ;)
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rotarypwrAuthor Commented:
This is exactly what I was trying to figure out!  If I want to allow all VLANs, can I do that without having to indicate each VLAN individually?
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Craig BeckCommented:
Yes, to allow all VLANs you just don't include the switchport trunk allowed vlan 10-20 line.  This then implies all VLANs are allowed to pass through the trunk.
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Ernie BeekExpertCommented:
Can't add anything to that.

(slow typing 'n stuff......  :)
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rotarypwrAuthor Commented:
Thank you very much.  Excellent solutions.
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