Multicast-Enabled Address Resolution Protocol (ME-ARP)
A Multicast-Enabled Address Resolution Protocol (ME-ARP) is disclosed. This ME-ARP allows the building of independent IP based Virtual Private LAN segments (VPLS) over a multicast enabled IP backbone using stateless tunnels and optimal VPLS traffic forwarding. Each VPLS has an associated IP subnet which is completely independent from other VPLS or the underlying IP backbone itself. Each Customer Premises Equipment (CPE) device needs only to be configured with a VPLS identifier and its serving IP subnet per VPLS designated interface.
1 - 10 . (canceled)
11 . A method of forwarding traffic in a virtual private local area network service (VPLS), the method comprising:
assigning to a virtual private local area network providing a VPLS a virtual private network internet protocol (VPN-IP) multicast address that is unique to the VPLS;
joining an interface of customer premises equipment (CPE) to a multicast group of a virtual private network (VPN);
encapsulating traffic with the VPN-IP multicast address; and
forwarding the encapsulated traffic based on the VPN-IP multicast address.
12 . The method according to claim 11 , wherein the joining the interface of the CPE to the multicast group comprises using Internet Group Management Protocol (IGMP).
13 . The method according to claim 12 , wherein the joining the interface of the CPE using IGMP comprises joining the interface of the CPE to the multicast group by using the IGMP with a multicast-capable routing protocol.
14 . The method according to claim 13 , wherein the multicast-capable routing protocol comprises a distance vector multicast routing protocol (DVMRP).
15 . The method according to claim 13 , wherein the multicast-capable routing protocol comprises a multicast open shortest path first (MOSPF) protocol.
16 . The method according to claim 13 , wherein the multicast-capable routing protocol comprises a protocol independent multicast (PIM) protocol.
17 . The method according to claim 11 , further comprising keeping track of the joined interface of the CPE using the VPN-IP multicast address.
18 . The method according to claim 11 , further comprising configuring the CPE with configuration information comprising a virtual private network multicast identifier associated with the internet protocol address of the VPLS.
19 . The method according to claim 11 , further comprising configuring the CPE with configuration information comprising an internet protocol network mask.
20 . The method according to claim 11 , further comprising configuring the CPE with configuration information comprising a tunnel internet protocol address.
21 . The method according to claim 11 , further comprising configuring the CPE with configuration information comprising a media-access-control (MAC) address calculation algorithm.
22 . The method according to claim 11 , further comprising:
encapsulating an address resolution protocol (ARP) request matching a customer's IP subnet; and
forwarding the encapsulated ARP request to the VPN-IP multicast address of the VPLS.
23 . The method according to claim 22 , further comprising:
receiving a forwarded encapsulated ARP request;
decapsulating the received encapsulated ARP request; and
replacing a source hardware address of the decapsulated ARP request with a calculated address containing a tunnel source internet protocol address, a virtual private network identifier and a customer premises equipment identifier.
24 . The method according to claim 11 , further comprising creating an entry in an address resolution protocol table (ARP table) for caching, the ARP table being associated with the CPE.
25 . The method according to claim 11 , wherein the traffic is encapsulated in an encapsulation-without-security format.
26 . The method according to claim 11 , wherein the traffic is encapsulated in an encapsulation-with-authentication-only format.
27 . The method according to claim 11 , wherein the traffic is encapsulated in an encapsulation-with-encryption format.
28 . The method according to claim 11 , wherein the interface of the CPE is an unnumbered VPN-IP interface.