Nexus N7706 with F3-348XP-23 line card VDC port allocation.

[daemibros]

While i have worked with Nexus for some time, i have never had to assign more than 12 ports to one VDC and some of the old cards did not have certain restrictions.  I seemed to be getting conflicting information from different documents

On the F3-348XP-23 line card, installed on a N7706

1. Can i assign port p1 to 24 in one VDC and p25 to 40 in a different VDC regardless of the port allocations in the link below which has this diagram. 

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus7000/sw/vdc/config/cisco_nexus7000_vdc_config_guide_8x/managing-vdc.html

Correct me if am wrong, My understanding of information in the above link is i am limited to just 16 ports (1-8 & 33-40)  or (25-32 and 41 to 48) 

2. Being that i want to use MACSEC for the two separate VDCs, Are there any restrictions in splitting the ports 41 to 48 between the two VDC say 41 to 44 in one VDC and 45 to 48 in second VDC? 

Any extra documentation to help clarify will very appreciated. 

Thanks 

[Sergiu.Daniluk]

Hi @daemibros 

I know this is an old thread and old question, and you might have already found the answer, however, I would like to clarify this, as there might be people having similar queries.

First, all Nexus 7000/7700 have the interfaces bound together into something called port-groups. As you know, interfaces can be allocated from one VDC to another, but the only restriction regarding port allocation is that if you want to move a port, you need allocate the full port-group.

As a practical example, let's take N77-F348XP-23. This is how ports are allocated into the port-groups:

Table 14. Port Numbers for Port Groups on the Cisco Nexus 7000 Series 10-Gbps Ethernet Modules (N7K-F348XP-25) and the Cisco Nexus 7700 Series 10-Gbps Ethernet Modules (N77-F348XP-23)

Group 1	1, 2, 3, 4, 5, 6, 7, 8
Group 2	9, 10, 11, 12, 13, 14, 15, 16
Group 3	17, 18, 19, 20, 21, 22, 23, 24
Group 4	25, 26, 27, 28, 29, 30, 31, 32
Group 5	33, 34, 35, 36, 37, 38, 39, 40
Group 6	41, 42, 43, 44, 45, 46, 47, 48

Reference: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus7000/sw/vdc/config/cisco_nexus7000_vdc_config_guide_8x/managing-vdc.html 

This means that if you want to move port 41 to a VDC, you need to move all 8 ports into that VDC. There is no exception to this rule. In fact, while doing the "allocate" command, there will be a prompt notifying you that all 8 ports part of the port-group will be moved.

Hope this helps!

Stay safe,

Segiu