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Nexus1000v Port-channel,Mac-pinning

mhasabal
Level 1
Level 1

Hello,

I have some questions if you can help me out please.

1-Just need to understand the difference between configuring port-channel mac-pinning Vs port-channel LACP on the Nexus1000v? what do i gain or loose by having one versus the other?

2-when configuring port-ch LACP on both side, the 2 upsteam switches (Nexus7000) need to be on VPC? does that mean vpc the port-ch or running 2 10G links between the Nexus7000 switches.

i ran into an issue when i am configuring port-channel LACP or on on the both side my links show all up but i am not switching. i don't have any control or visibilty into the upsteam switch.

my understanding is on the upsteam switches i need to have 2 indvidual 10G links configured with vpc and creating port-ch interface and vpc the interface as well.

please let me know if i am making any sense.

thanks in advance

2 Replies 2

Robert Burns
Cisco Employee
Cisco Employee
1-Just need to understand the difference between configuring port-channel mac-pinning Vs port-channel LACP on the Nexus1000v? what do i gain or loose by having one versus the other?

A Port Channel using LACP (mode active) or Static (mode on) offer a single logical aggregated link made up of up to eight active links.  Traffic traversing a port channel is hashed by a number of pre-defined options to give you the best distributed load across active channel members.  Rather than a flow be limited to a single link, the flow can be spread across mulitple link in a port channel.  Port channels require configuration on both the N1K and upstream switch side.  LACP is a negociated channeling protocol that can monitor the health of member links and shut them down if there's any issues.  Static port channels "are just up" and offer no enhanced health checking mechanisms.

MAC-Pinning on the other hand treats each uplink individualy.  This is similar to how the vSwitch handles multiple uplinks (by default).  Each VM's traffic is "pinned" to an uplink.  If any single uplink becomes saturated it can impact any other VMs pinned to the same link.  Upon failure and pinned VMs will get re-pinned automatically to another availalbe uplink.  MAC pinning is a simple approach to uplinks because unlike a Port channel there is NO upstream channeling configuration required.

The decision to use either comes down to 1) Switch capability and 2) Bandwidth requirements.  If you only have a single physical switch, or multple upstream that can be clustered (VSS, vPC, Stack, VBS), then Port channelling is the preferred option.  MAC pinning is a great fit if you have multiple upstream switches that can't be clustered or do not support channeling.  Though MAC pinning doesn't offer aggregated bandwidth of uplinks, it's simplicity make it very appealing to customers. 

2-when configuring port-ch LACP on both side, the 2 upsteam switches (Nexus7000) need to be on VPC? does that mean vpc the port-ch or running 2 10G links between the Nexus7000 switches.

Yes.  When uplinking a single VEM host to two N7K's, you can do an LACP vPC.  This offeres a single aggregated multichassis link..  The two N7K's need to be "vPC Peers" which requires you to configure a vPC Peer link interconnecting them.  

i ran into an issue when i am configuring port-channel LACP or on on the both side my links show all up but i am not switching. i don't have any control or visibilty into the upsteam switch.

my understanding is on the upsteam switches i need to have 2 indvidual 10G links configured with vpc and creating port-ch interface and vpc the interface as well.

please let me know if i am making any sense.

Before you can setup vPC to your hosts, the N7K's, but have the vPC feature enabled, and be correctly configured as Peers. 

Have a read through these docs so you have a firm understanding of vPC operation and it's configuration:

vPC Whitepaper:

http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9402/white_paper_c11-516396.html

vPC Configuration Guide:

http://www.cisco.com/en/US/docs/switches/datacenter/sw/5_x/nx-os/interfaces/configuration/guide/if_vPC.html

Regards,

Robert

Robert,

thank you so much for the great information.

i have one more question for you please.

I am going to change the vmnic port-profile from Mac-pining to LACP

when doing the changes what do you recommend? can you think of any possible issue ?

can i just issue the command ch-group mode auto active first then remove the mac-pining

currently i have the service console behind the N1K

again thank you Robert

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