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Pablo Vicencio

Nexus 5500 and FEX Port-channel


I have been starting to read a lot of this tech but I still have some doubts regarding port-channel limits in my platform.

So this is my current set up:

- 1 Nexus N5K-C5596UP

- 2 Fabric Extenders N2K-C2148T-1GE.

Currently  the Fabric Extenders are connected to the C5596UP, and they have been  attached correctly, and everything is working fine:

LAB# show fex

  FEX         FEX           FEX                       FEX              

Number    Description      State            Model            Serial    


110        FEX0100                Online      N2K-C2148T-1GE   FOX123455666

120        FEX0200                Online      N2K-C2148T-1GE   FOX123123234

I have been reading this DOC:

There I read that:

- There are differences between Nexus 5000 and 5500 mostly because port density of 5500.

- There are something called "index" which have a limitation of 48.

- In 5500 every single port can be a port-channel itself.

- Those index can be used either by using a single port, several ports or bundles of ports.

- If the nexus use one of their hardware ports it will use one index.

- On the other hand, If the nexus doesnt use its hardware ports, It won't use those index.

- The document also describes that if the port-channel just use FEX ports, it won't use an index.

I also read this document that describes limitations of interfaces per bundle up to 16.

So after of read that I still have some questions:

1. If I configure port-channels just using fex ports, I wont use indexes but, there are still limitations on it?.

2. How many port-channels can be configured on a single FEX?

3. How many port-channels can be configured if I am using ports that belongs to diferent FEX?.

4. How many port-channels can be configured using hardware ports?

5. How can I check how many available indexes left?

6. There is a limitation of port-channels based on version?

7. 16 ports as limit applies to every port-channel configured?

Thank you for all your support.


Cisco Employee

Hello Pablo,

Is important to know which version of nxos you are running on 5596UP and if you have L3 card.

There are many difference between 5000 and 5500 plataforms, not just ports.

I guess that all your questions can be answered by this reference:



Thank you so much for the answer, this is the show version:


N5K-LAB# show version

Cisco Nexus Operating System (NX-OS) Software

TAC support:


Copyright (c) 2002-2012, Cisco Systems, Inc. All rights reserved.

The copyrights to certain works contained herein are owned by

other third parties and are used and distributed under license.

Some parts of this software are covered under the GNU Public

License. A copy of the license is available at


  BIOS:      version 3.6.0

  loader:    version N/A

  kickstart: version 5.1(3)N1(1a)

  system:    version 5.1(3)N1(1a)

  power-seq: Module 1: version v4.0

  uC:        version v1.0.0.2

  SFP uC:    Module 1: v1.0.0.0

  BIOS compile time:       05/09/2012

  kickstart image file is: bootflash:///n5000-uk9-kickstart.5.1.3.N1.1a.bin

  kickstart compile time:  2/7/2012 23:00:00 [02/08/2012 07:49:30]

  system image file is:    bootflash:///n5000-uk9.5.1.3.N1.1a.bin

  system compile time:     2/7/2012 23:00:00 [02/08/2012 12:44:33]


  cisco Nexus5596 Chassis ("O2 48X10GE/Modular Supervisor")

  Intel(R) Xeon(R) CPU         with 8263880 kB of memory.

  Processor Board ID FOC123123213

  Device name: N5K-LAB

  bootflash:    2007040 kB

Last reset

  Reason: Unknown

  System version: 5.1(3)N1(1a)



  Core Plugin, Ethernet Plugin, Fc Plugin


I've already seen that table but I still have some doubts because, for example:

In this guide said that "The number of bundles that can be indexed on the Cisco Nexus 5500 platform is 48" but, in this other guide said that  the "Number of Switch port EtherChannels" is 96 in "96- Nexus 5596 switch".

So, Is the max number 48 or 96?


Hello Pablo,

The maximum port EtherChannels is 96 in Nexus 5596 platform according the last nxos release software. This number refers only aggregation to connect fex links.

About port-channel to connect hosts or others devices the number maximum is 1152 with fex/Layer 2 topology and 768 with fex/L3 topology.

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