Routing internet protocol version 6 link-local addresses in a network environment

摘要

An example method for routing IPv6 link-local addresses in a network environment is provided and includes receiving a packet at a first switch from an attached first host in a virtual local area network (VLAN) associated with a virtual routing and forwarding (VRF) instance of a network environment, where the packet is destined to an Internet Protocol version 6 (IPv6) link-local address of a remote second host in the VLAN, and routing the packet at Layer 3 to a second switch, to which the second host is attached. In specific embodiments, the second switch routes the packet at Layer 3 to the second host if the VRF does not include duplicate IPv6 link-local addresses corresponding to the IPv6 link-local address of the second host; the second switch bridges the packet at Layer 2 to the second host if the VRF includes at least one duplicate IPv6 link-local address.

主权项

1. A method, comprising:
receiving a packet at a first switch from a directly attached first host in a virtual local area network (VLAN) associated with a virtual routing and forwarding (VRF) instance of a network environment, wherein the packet is destined to an Internet Protocol version 6 (IPv6) link-local address of a remote second host in the VLAN, the IPv6 link-local address being unique within only the VLAN; installing a destination value in a destination Media Access Control (MAC) address field of a Layer 3 forwarding table in the first switch; setting an egress VLAN value in the Layer 3 forwarding table to the VLAN based on a value of a preserve-VLAN (PV) bit, wherein the PV bit is set to a value of 1 for link-local addresses, wherein the value of 1 for the PV bit indicates that an egress VLAN determined by the first switch and represented by the egress VLAN value is the same as the VLAN; and routing the packet at Layer 3 to a second switch, to which the second host is directly attached, wherein if the VRF does not include duplicate IPv6 link-local addresses corresponding to the IPv6 link-local address of the second host, the destination value comprises a router MAC address of the second switch and the second switch routes the packet at Layer 3 to the second host, and wherein if the VRF includes at least one duplicate IPv6 link-local address corresponding to the IPv6 link-local address of the second host, the destination value comprises a MAC address of the second host and the second switch bridges the packet at Layer 2 to the second host.