In a Cisco NFVI C-Series Pod, the Top-of-Rack (ToR) switches are almost always configured as a vPC pair. A vPC domain requires three mandatory components:

vPC domain ID

vPC peer-link

vPC peer-keepalive link ensures dual-active detection

In the exhibit:

The management interfaces are Tor-A Mgmt0: 10.10.10.1 and Tor-B Mgmt0: 10.10.10.2

These IPs are used commonly as the peer-keepalive endpoints

The physical uplinks to NFVI nodes form Port-Channel110

Since the configuration snippet already includes:

feature vpc

feature lacp

channel-group 110 mode active

The next required step in a Cisco NFVI + vPC configuration is to configure the peer-keepalive from ToR-A toward ToR-B:

vpc domain 1

peer-keepalive destination 10.10.10.2

This ensures:

vPC roles sync

Dual-active prevention

Stable operation for the NFVI C-Series rack

Why the Other Options Are Incorrect

A. vpc peer-link This is required but must be configured on the dedicated peer-link interfaces, not on the server-facing port-channel.

C. channel-group 110 mode on The correct mode is already configured: mode active for LACP. mode on disables LACP.

D. switchport mode access NFVI ToR links use trunking, not access mode, because servers carry multiple networks (control, compute, storage, management VLANs).