You are leading design discussions about IPv6 implementation into an existing Enterprise network. A question is raised regarding older Layer 2 switches that exist in the network, and if any changes…

DHCPv6 operates at Layer 3 and is relayed or terminated by Layer 3 devices - Layer 2 switches only need to forward DHCPv6 frames transparently and do not require specific DHCPv6 support for anycast operation.

For IPv6 anycast deployments, Layer 2 switches should support Neighbor Discovery (ND) inspection to validate ND messages, prevent ND spoofing, and ensure proper address resolution for anycast addresses at Layer 2.

While Layer 2 switches forward IPv6 frames transparently in basic scenarios, this blanket statement is incorrect because multicast and security features like MLD snooping and ND inspection do require specific IPv6-aware capabilities in Layer 2 switches.

MLD (Multicast Listener Discovery) is the IPv6 counterpart to IGMPv2/v3 - Layer 2 switches must support MLD snooping to track IPv6 multicast group memberships and avoid flooding multicast traffic to all ports in a VLAN.

ICMPv6 frames are forwarded transparently by Layer 2 switches as standard Ethernet frames and no special Layer 2 switch configuration is needed to support ICMPv6 for anycast to function.