Multicast VPN support for IP-VPN lite
Techniques disclosed herein include systems and methods for providing multicast Virtual Private Network (VPN) support for IP VPN networks, including IP VPN-lite networks. Such techniques provide multicast VPN capability over an IP unicast core network by creating a multicast service VLAN and IP interface, which is used for multicast control traffic exchange between VPN instances. Multicast VPN data traffic is then carried over unicast IP-in-IP tunnels. A given ingress Provide Edge (PE) replicates the multicast traffic for all receiving egress PEs, and adds control information so that the multicast traffic appears as unicast traffic to the Core network. With such a technique, a given Core network only needs to run an IP unicast that is free of VPN unicast or multicast route or tree information.
1. A computer-implemented method for multicast data communication, the computer-implemented method comprising:
examining control information of a multicast data packet received at a first data switching device, the multicast data packet including control information and a payload, the multicast data packet received as part of a virtual private network (VPN);
identifying remotely attached data switching devices to which to forward the multicast data packet based on the control information, the remotely attached data switching devices being logically connected to the first data switching device via a service provider network, wherein identifying remotely attached data switching devices to which to forward the multicast data packet based on the control information includes identifying remotely attached virtual route forwarders;
replicating the multicast data packet for each identified remotely attached data switching device;
encapsulating each replicated multicast data packet with outer header information, the outer header information identifying each replicated multicast data packet as a unicast data packet;
forwarding each encapsulated and replicated multicast data packet to a corresponding remotely attached data switching device via a logical unicast tunnel of the service provider network;
exchanging VPN routing information with remotely attached switching devices using Multi-Protocol extensions to Border Gateway Protocol (MP-BGP), each data switching device having one or more virtual route forwarders; and
enabling a multicast routing protocol in each virtual route forwarder.
2. The computer-implemented method of claim 1 , further comprising:
receiving, via the logical unicast tunnel within the service provider network, a second multicast data packet from a remotely attached data switching device, the second multicast data packet being encapsulated with an outer header identifying the second multicast data packet as a unicast data packet;
decapsulating the outer header of the second multicast data packet; and
executing a multicast routing operation on the second multicast data packet based on corresponding control information.
3. The computer-implemented method of claim 2 , wherein executing the multicast routing operation on the second multicast data packet based on corresponding control information comprises:
examining the decapsulated second multicast data packet in a virtual route forwarder of the first data switching device;
encapsulating the decapsulated second multicast data packet with an Ethernet header; and
forwarding the second multicast data packet with the Ethernet header to a corresponding Customer Edge device locally attached to the first data switching device.
4. The computer-implemented method of claim 1 , wherein identifying remotely attached data switching devices to which to forward the multicast data packet includes executing a VPN classification of the multicast data packet, the multicast data packet being received from a Customer Edge device, the first data switching device being a Provider Edge device.
5. The computer-implemented method of claim 4 , further comprising:
wherein encapsulating each replicated multicast data packet with outer header information includes Internet Protocol (IP) encapsulation of IP data packets, the logical unicast tunnel of the service provider network using an IP unicast protocol.
6. The computer-implemented method of claim 1 , further comprising:
connecting Protocol Independent Multicast (PIM) instances within the virtual route forwarders of the VPN using an extended Virtual Local Area Network (VLAN), the VLAN including an Internet Protocol (IP) interface.
7. The computer-implemented method of claim 1 , further comprising:
replicating the multicast data packet for each directly attached Customer Edge (CE) device; and
forwarding replicated multicast data packets to corresponding CE devices without encapsulating the multicast data packet with the unicast outer header information.
8. A computer system for multicast data communication, the computer system comprising:
a processor; and
a memory coupled to the processor, the memory storing instructions that, when executed by the processor, cause the system to perform the operations of:
examining control information of a multicast data packet received at a first data switching device, the multicast data packet including control information and a payload, the multicast data packet received as part of a virtual private network (VPN);
identifying remotely attached data switching devices to which to forward the multicast data packet based on the control information, the remotely attached data switching devices being logically connected to the first data switching device via a service provider network, wherein identifying remotely attached data switching devices to which to forward the multicast data packet based on the control information includes identifying remotely attached virtual route forwarders;
replicating the multicast data packet for each identified remotely attached data switching device;
encapsulating each replicated multicast data packet with outer header information, the outer header information identifying each replicated multicast data packet as a unicast data packet;
forwarding each encapsulated and replicated multicast data packet to a corresponding remotely attached data switching device via a logical unicast tunnel of the service provider network;
exchanging VPN routing information with remotely attached switching devices using Multi-Protocol extensions to Border Gateway Protocol (MP-BGP), each data switching device having one or more virtual route forwarders; and
enabling a multicast routing protocol in each virtual route forwarder.
9. The computer system of claim 8 , the memory storing further instructions that, when executed by the processor, cause the system to perform the operations of:
receiving, via the logical unicast tunnel within the service provider network, a second multicast data packet from a remotely attached data switching device, the second multicast data packet being encapsulated with an outer header identifying the second multicast data packet as a unicast data packet;
decapsulating the outer header of the second multicast data packet; and
executing a multicast routing operation on the second multicast data packet based on corresponding control information.
10. The computer system of claim 9 , wherein executing the multicast routing operation on the second multicast data packet based on corresponding control information comprises:
examining the decapsulated second multicast data packet in a virtual route forwarder of the first data switching device;
encapsulating the decapsulated second multicast data packet with an Ethernet header; and
forwarding the second multicast data packet with the Ethernet header to a corresponding Customer Edge device locally attached to the first data switching device.
11. The computer system of claim 8 , wherein identifying remotely attached data switching devices to which to forward the multicast data packet includes executing a VPN classification of the multicast data packet, the multicast data packet being received from a Customer Edge device, the first data switching device being a Provider Edge device.
12. The computer system of claim 11 , wherein encapsulating each replicated multicast data packet with outer header information includes Internet Protocol (IP) encapsulation of IP data packets, the logical unicast tunnel of the service provider network using an IP unicast protocol.
13. The computer system of claim 8 , the memory storing further instructions that, when executed by the processor, cause the system to perform the operations of:
connecting Protocol Independent Multicast (PIM) instances within the virtual route forwarders of the VPN using an extended Virtual Local Area Network (VLAN), the VLAN including an Internet Protocol (IP) interface.
14. The computer system of claim 8 , the memory storing further instructions that, when executed by the processor, cause the system to perform the operations of:
replicating the multicast data packet for each directly attached Customer Edge (CE) device; and
forwarding replicated multicast data packets to corresponding CE devices without encapsulating the multicast data packet with the unicast outer header information.
15. A computer program product including a non-transitory computer-storage medium having instructions stored thereon for processing data information, such that the instructions, when carried out by a processing device, cause the processing device to perform the operations of:
examining control information of a multicast data packet received at a first data switching device, the multicast data packet including control information and a payload, the multicast data packet received as part of a virtual private network (VPN);
identifying remotely attached data switching devices to which to forward the multicast data packet based on the control information, the remotely attached data switching devices being logically connected to the first data switching device via a service provider network, wherein identifying remotely attached data switching devices to which to forward the multicast data packet based on the control information includes identifying remotely attached virtual route forwarders;
replicating the multicast data packet for each identified remotely attached data switching device;
encapsulating each replicated multicast data packet with outer header information, the outer header information identifying each replicated multicast data packet as a unicast data packet;
forwarding each encapsulated and replicated multicast data packet to a corresponding remotely attached data switching device via a logical unicast tunnel of the service provider network;
exchanging VPN routing information with remotely attached switching devices using Multi-Protocol extensions to Border Gateway Protocol (MP-BGP), each data switching device having one or more virtual route forwarders; and
enabling a multicast routing protocol in each virtual route forwarder.
16. The computer program product of claim 15 , having further instruction that cause the processing device to perform the operations of:
receiving, via the logical unicast tunnel within the service provider network, a second multicast data packet from a remotely attached data switching device, the second multicast data packet being encapsulated with an outer header identifying the second multicast data packet as a unicast data packet;
decapsulating the outer header of the second multicast data packet; and
executing a multicast routing operation on the second multicast data packet based on corresponding control information.