Efficient VPN route refresh mechanism for BGP based VPN technologies

1. A method implemented by a network device, the method to optimize an operation of a virtual private network (VPN) route refresh for border gateway protocol (BGP), the method to reduce a span of VPN databases to be traversed to perform the VPN route refresh at the network device, the method comprising:

receiving a route target constraint (RTC) add or delete from a BGP peer;

looking up each route target (RT) in a route target route distinguisher (RT-RD) map to get a set of route distinguishers (RDs); and

generating a VPN update for each VPN Address Family (AF) and each RD in an RD cache and sending the VPN update to a respective BGP peer;

the method further comprising:

adding the RTC add or delete to a timer; and

performing an update transaction when the timer expires.

2. The method of claim 1 , further comprising:

updating a RT filter for each peer affected by the RTC add or delete.

3. The method of claim 1 , further comprising:

identifying a changeset for each RT filter of each BGP peer.

4. The method of claim 1 , further comprising:

adding a set of RDs to an RD cache of a respective BGP peer.

5. A network device to optimize an operation of a virtual private network (VPN) route refresh for border gateway protocol (BGP), the network device to reduce a span of VPN databases to be traversed to perform the VPN route refresh at the network device, the network device comprising:

a non-transitory computer readable medium having stored therein a VPN route refresher; and

a processor coupled to the non-transitory computer readable medium, the processor to execute the VPN route refresher, the VPN route refresher to receive a route target constraint (RTC) add or delete from a BGP peer, to look up each route target (RT) in a route target-route distinguisher (RT-RD) map to get a set of route distinguishers (RDs), and to generate a VPN update for each VPN Address Family (AF) and each RD in an RD cache and sending the VPN update to a respective BGP peer,

wherein the VPN route refresher is further to add the RTC add or delete to a timer, and to perform an update transaction when the timer expires.

6. The network device of claim 5 , wherein the VPN route refresher is further to update a RT filter for each peer affected by the RTC add or delete.

7. The network device of claim 5 , wherein the VPN route refresher is further to identify a changeset for each RT filter of each BGP peer.

8. The network device of claim 5 , wherein the VPN route refresher is further to add a set of RDs to an RD cache of a respective BGP peer.

9. A computing device implementing a plurality of virtual machines for implementing network function virtualization (NFV), wherein a virtual machine from the plurality of virtual machines is configured to execute a method to optimize an operation of a virtual private network (VPN) route refresh for border gateway protocol (BGP), the computing device to reduce a span of VPN databases to be traversed to perform the VPN route refresh at the computing device, the computing device comprising:

a non-transitory computer readable medium having stored therein a VPN route refresher; and

a processor coupled to the non-transitory computer readable medium, the processor to execute the virtual machine from the plurality of virtual machines, the virtual machine to execute the VPN route refresher, the VPN route refresher to receive a route target constraint (RTC) add or delete from a BGP peer, to look up each route target (RT) in a route target-route distinguisher (RT-RD) map to get a set of route distinguishers (RDs), and to generate a VPN update for each VPN Address Family (AF) and each RD in an RD cache and sending the VPN update to a respective BGP peer,

wherein the VPN route refresher is further to add the RTC add or delete to a timer, and to perform an update transaction when the timer expires.

10. The computing device of claim 9 , wherein the VPN route refresher is further to update a RT filter for each peer affected by the RTC add or delete.

11. The computing device of claim 9 , wherein the VPN route refresher is further to identify a changeset for each RT filter of each BGP peer.

12. The computing device of claim 9 , wherein the VPN route refresher is further to add a set of RDs to an RD cache of a respective BGP peer.

13. A control plane device configured to implement at least one centralized control plane for a software defined networking (SDN) network, the centralized control plane configured to execute a method to optimize an operation of a virtual private network (VPN) route refresh for border gateway protocol (BGP), the control plane device to reduce a span of VPN databases to be traversed to perform the VPN route refresh at the control plane device, the control plane device comprising:

a non-transitory computer readable medium having stored therein a VPN route refresher; and

a processor coupled to the non-transitory computer readable medium, the processor to execute the VPN route refresher, the VPN route refresher to receive an RTC add or delete from a BGP peer, to look up each route target (RT) in a route target-route distinguisher (RT-RD) map to get a set of route distinguishers (RDs), and to generate a VPN update for each VPN Address Family (AF) and each RD in an RD cache and sending the VPN update to a respective BGP peer,

wherein the VPN route refresher is further to add the RTC add or delete to a timer, and to perform an update transaction when the timer expires.

14. The control plane device of claim 13 , wherein the VPN route refresher is further to update a RT filter for each peer affected by the RTC add or delete.

15. The control plane device of claim 13 , wherein the VPN route refresher is further to identify a changeset for each RT filter of each BGP peer.

16. The control plane device of claim 13 , wherein the VPN route refresher is further to add a set of RDs to an RD cache of a respective BGP peer.