A company is expanding its existing office space to a new floor of the building, and the networking team is installing a new set of switches. The new switches are running IGMPv2, and the engineers…

Configuring new switches for "all VLANs on the network" is excessive, as they are explicitly mentioned to be configured for VLAN10 only and may not be responsible for other VLANs.

This option suggests a network-wide configuration of both IGMPv2 and IGMPv3 support on all VLANs. While IGMPv3 is backward compatible, explicitly configuring all switches for dual-mode on all VLANs is unnecessarily broad and inefficient when the issue is localized to VLAN10 and new switches.

The most effective solution for IGMP interoperability is to run the highest common IGMP version across all devices. Since the existing network uses IGMPv3 and the new switches are relevant for VLAN10, configuring the new switches to use IGMPv3 on VLAN10 only will ensure full compatibility and optimal multicast routing for that specific VLAN without unnecessary configuration on other VLANs or existing switches.

While limiting the scope to VLAN10 is better than "all VLANs", explicitly configuring *all* switches for dual IGMPv2/v3 support is less optimal than simply upgrading the new switches to IGMPv3 where it's needed, especially since existing switches already run IGMPv3.