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3750X etherchannel with different capacity interfaces

johnramz
Level 1
Level 1

Image: C3750e-ipbasek9-mz.122-58.SE2.bin"

Two stacks of 4 switches each

Each stack has one module : C3KX-NM-10GT

So I could create a 20--GBit erherchannel. But what If I want to create a 22-Gbit etherchannel?

Could I use the Two(2) 10-Gbit interfaces on each stack plus Two(2) 1-Gbit interfaces on EACH stack ?

Is this doable? Does fall out of best practices?

If yes please provide CISCO document that supports it.

Thanks

Juan

9 Replies 9

Leo Laohoo
Hall of Fame
Hall of Fame
But what If I want to create a 22-Gbit etherchannel?

Won't work.  Not unless you've manage to find two 11 Gbps ports.

Most important rule-of-thumb with Etherchannels:  Each physical interface need to be the same speed.

Thanks Leo. I figured that was the answer "All LAN ports in each EtherChannel must be the same speed, and you must configure all the ports as either Layer 2 or Layer 3 LAN ports." according to the link provided by Ankur.

We currently have a 2-GB etherchannel between those two stacks. so what I might do is to set up a new 20-GB etherchannel and let STP take care of keeping the 2-GB link in passive mode.

Juan

Ankur Arora
Level 1
Level 1

Hi,

You won't be able to create a 22Gig etherchannel using two 10gig ports and two 1gig ports.

As all the interfaces in an etherchannel should have the exact same speed.

You may go through the below document:

http://www.cisco.com/c/en/us/support/docs/lan-switching/etherchannel/12023-4.html#catalyst

Thanks

Ankur

"Please rate the post if found useful"

Thanks Ankur.

We currently have a 2-GB etherchannel between those two stacks. so what I might do is to set up a new 20-GB etherchannel and let STP take care of keeping the 2-GB link in passive mode.

Juan

Joseph W. Doherty
Hall of Fame
Hall of Fame

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

Just to add to what the others have already noted.  You can use different media, e.g. fiber and copper, but again, both need to be same "speed".

If you only have one module in your stack, you can have 4 gig, 2 10g, or 2 gig and 1 10g.  I.e. you cannot have 22 gig, even without Etherchannel.

Thanks Joseph.

We currently have a 2-GB etherchannel between those two stacks. so what I might do is to set up a new 20-GB etherchannel and let STP take care of keeping the 2-GB link in passive mode.

Juan

Disclaimer

The   Author of this posting offers the information contained within this   posting without consideration and with the reader's understanding that   there's no implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not   be construed as rendering professional advice of any kind. Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In   no event shall Author be liable for any damages whatsoever (including,   without limitation, damages for loss of use, data or profit) arising  out  of the use or inability to use the posting's information even if  Author  has been advised of the possibility of such damage.

Posting

We currently have a 2-GB etherchannel between those two stacks. so what I might do is to set up a new 20-GB etherchannel and let STP take care of keeping the 2-GB link in passive mode.

Ah, so you have more than one fiber module per stack, or will your dual gig Etherchannel use "ordinary" copper ports?

Reason I ask, again, when you use a SFP+ port, as 10g, you cannot use the adjacent SFP port.  See Table 4 in: http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-3750-x-series-switches/data_sheet_c78-584733.html

[edit]

The above applies to a C3KX-NM-10G, but as your OP noted you have a single C3KX-NM-10GT, it only supports copper 10g.  You're limited to two 10g ports.

Thanks Joseph.

The current 2-gig etherchannel uses ordinary copper ports. So I should still be able to add a new 20-gig etherchannel.

Juan

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

Ok, that's fine, but do know the ordinary 3750X copper ports have 2 MB buffer RAM, while the module ports also get 2 MB buffer RAM.  If your uplinks are busy, they might perform better on uplink ports.

Also, having the second set of gig Etherchannel will only be used if both 10g links failed.  If one 10g link is up, STP should see it as a better path.

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