ACI vpc domain consecutive

[Johannes Luther]

Hi board,

i'm pretty new to ACI and have a question regarding the building of vPCs between two leaf nodes.

There is either the way to "bundle" two leaf nodes statically or dynamically to a vPC domain.

I think the dynamic mode is cool, but I don't get quite the point.

Config is:

vpc domain consecutive

Assuming I have five leaf nodes with the IDs 1001, 1002, 1004, 2001, 2002

How are the vPCs built?

Option 1: DIRECTLY consecutive

vPC domain 1: 1001, 1002

vPC domain 2: 2001, 2002

no vPC domain for 1004

Option 2: not DIRECTLY consecutive

vPC domain 1: 1001, 1002

vPC domain 2: 1004, 2001

no vPC domain for 2002

Anybody got an idea?

[micgarc2]

The key differences to note here are that relative to traditional vPC design, there is no requirement for setting up vPC peer-links. Also, there are no keepalives that are sent on management port. The fabric itself serves as the peer-link. 

You create an explicit vPC protection group for the two switches you want apart of the vPC. After creation, the APIC will allocate a VTEP to that VPC pair. 

ex:

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Regards,

Michael G.

[Johannes Luther]

Hi Michael,

thank you for the feedback. So until now I did everything correct - I didn't set up a peer link :)

However from my understanding you have to tell the fabric which two leaf switches form a vpc peer.

In your screenshot you manually (explicetely) set up the nodes 101 and 103 as a vpc group (group 101) and the nodes 204 and 206 as another group (group 204).

In ACI there is the option to automatically group two leaf nodes depending on the node id

(mode consecutive instead of explicit).

My question was referring to the consecutive mode.

For example:

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/2-x/L2_config/b_Cisco_APIC_Layer_2_Configuration_Guide/b_Cisco_APIC_Layer_2_Configuration_Guide_chapter_0100.html

=> Search for "explicit" and/or "consecutive"

[micgarc2]

Yes:

[Johannes Luther]

:) So the original question remains:

If the setting is set to consecutive how are the vPCs built?

Assuming I have five leaf nodes with the IDs 1001, 1002, 1004, 2001, 2002

Option 1: DIRECTLY consecutive (direct successors)

vPC domain 1: 1001, 1002

vPC domain 2: 2001, 2002

no vPC domain for 1004

Option 2: not DIRECTLY consecutive

vPC domain 1: 1001, 1002

vPC domain 2: 1004, 2001

no vPC domain for 2002

[micgarc2]

That is a good question. I am not really sure. I would have to test. My guess is that it would be my node ID. So option 2 in your case.