Generating route distinguishers for virtual private network addresses based on physical hardware addresses
This disclosure describes techniques for improving route advertisements. In one example, a method includes generating, by a network device, a virtual private network address comprising a route distinguisher value and a network address associated with a compute node, the route distinguisher value based on a layer two physical hardware address of the compute node, and outputting, by the network device, a virtual private network route that includes the virtual private network address.
1 . A method comprising:
generating, by a software-defined networking (SDN) controller and as a function of a layer two (L2) physical hardware address of a network interface of a compute node, a route distinguisher value for distinguishing a network address associated with the compute node; and
outputting, by the SDN controller, a route that includes the route distinguisher value and the network address associated with the compute node.
2 . The method of claim 1 , further comprising:
receiving, by the SDN controller, the network address associated with the compute node in an overlay network route for a virtual network destination,
wherein generating the route distinguisher value comprises generating the route distinguisher value in response to receiving the overlay network route for the virtual network destination.
3 . The method of claim 2 , further comprising:
receiving, by the SDN controller, the L2 physical hardware address in the overlay network route for the virtual network destination.
4 . The method of claim 2 , wherein receiving the network address in the overlay network route comprises receiving a messaging protocol message specifying the network address.
5 . The method of claim 4 , and wherein the messaging protocol message is received via an Extensible Messaging and Presence Protocol (XMPP) session between a control node and a virtual router agent of the compute node, and wherein outputting the route comprises outputting the route via a Multi-Protocol Border Gateway Protocol (MP-BGP) session between the control node and a routing protocol peer device.
6 . The method of claim 1 , further comprising:
receiving the L2 physical hardware address in a message from the compute node, in response to an address resolution protocol request or a neighbor discovery protocol request.
7 . The method of claim 1 , wherein the route includes a route distinguisher field that specifies a Type field and a Value field, wherein data contained in the Type field indicates that data contained in the Value field of the route distinguisher field is generated as a function of a L2 physical hardware address, and wherein data contained in the Value field is the route distinguisher value generated as a function of the L2 physical hardware address of the network interface of the compute node.
8 . The method of claim 1 , wherein the compute node comprises a physical server, wherein the network interface is a control-data interface of the physical server, and wherein the L2 physical hardware address comprises a Media Access Control (MAC) address of the control-data interface of the physical server.
9 . The method of claim 1 , wherein the network address comprises one of an Internet Protocol version four or Internet Protocol version six address.
10 . The method of claim 1 , wherein outputting the route comprises outputting the route to a gateway router.
11 . The method of claim 10 , wherein the network address associated with the compute node is a virtual network address for a virtual network endpoint executed by the compute node, the method further comprising:
storing, by the gateway router, the route to a virtual routing and forwarding (VRF) instance for a virtual network that includes the virtual network endpoint; and
forwarding, by the gateway router, traffic to the compute node based on the route stored by the gateway router.
12 . The method of claim 10 , wherein the route is a virtual private network (VPN) route, the method further comprising:
learning, by the gateway router in response to receiving the VPN route from the SDN controller and based on data in the VPN route indicating the route distinguisher value was generated as a function of the L2 physical hardware address of the compute node, the L2 physical hardware address of the network interface of the compute node based on the route distinguisher value included in the VPN route; and
based on learning the L2 physical hardware address of the network interface of the compute node:
advertising, by the gateway router, the L2 physical hardware address of the network interface of the compute node in an Ethernet VPN route; and
forming, by the gateway router, a Virtual Extensible Local Area Network (VXLAN) tunnel directly with the compute node.
13 . A software-defined networking (SDN) controller comprising processing circuitry in communication with a memory, the processing circuitry being configured to:
generate, as a function of a layer two (L2) physical hardware address of a network interface of a compute node, a route distinguisher value for distinguishing a network address associated with the compute node; and
output a route that includes the route distinguisher value and the network address associated with the compute node.
14 . The SDN controller of claim 13 , wherein the processing circuitry is further configured to:
receive the network address associated with the compute node in an overlay network route for a virtual network destination; and
generate the route distinguisher value in response to receiving the overlay network route for the virtual network destination.
15 . The SDN controller of claim 14 , wherein the processing circuitry is further configured to receive the L2 physical hardware address in the overlay network route for the virtual network destination.
16 . The SDN controller of claim 14 , wherein the overlay network route comprises a messaging protocol message specifying the network address, and wherein the messaging protocol message is received via an Extensible Messaging and Presence Protocol (XMPP) session between a control node and a virtual router agent of the compute node, and
wherein to output the route comprises outputting the route via a Multi-Protocol Border Gateway Protocol (MP-BGP) session between the control node and a routing protocol peer device.
17 . The SDN controller of claim 13 , wherein the route includes a route distinguisher field that specifies a Type field and a Value field, wherein data contained in the Type field indicates that data contained in the Value field of the route distinguisher field is generated as a function of a L2 physical hardware address, and wherein data contained in the Value field is the route distinguisher value generated as a function of the L2 physical hardware address of the network interface of the compute node.
18 . The SDN controller of claim 13 , wherein the compute node comprises a physical server, wherein the network interface is a control-data interface of the physical server and wherein the L2 physical hardware address comprises a Media Access Control (MAC) address of the control-data interface of the physical server.
19 . The SDN controller of claim 13 , wherein the network address associated with the compute node is a virtual network address for a virtual network endpoint executed by the compute node, wherein to output the route comprises output the route to a gateway router to be stored by the gateway router to a virtual routing and forwarding (VRF) instance for a virtual network that includes the virtual network endpoint, such that the gateway router can forward traffic to the compute node based on the route.
20 . A method comprising:
generating, by a network device, a virtual private network route address comprising a network address associated with a compute node and a route distinguisher value for distinguishing the network address associated with a compute node, wherein the route distinguisher value is a function of a layer two physical hardware address of a network interface of the compute node; and
outputting, by the network device, the virtual private network route that includes the network address and the route distinguisher value.
21 . The method of claim 20 , wherein the network address associated with the compute node is a Layer 3 (L3) virtual network address for a virtual network endpoint executed by the compute node.