Asymmetric routing minimization
In some examples, an example method to minimize asymmetric routing at a network node may include maintaining a flow table including one or more records, each record indicating a packet flow and a corresponding tunnel, receiving a data packet to process at a network node, and determining whether to process the data packet as a follower node. The method may also include, responsive to a determination to process the data packet as a follower node, determining whether there is an entry in the flow table for a packet flow associated with the received packet, and, responsive to a determination that there is an entry in the flow table for the packet flow, transmitting the received data packet through a tunnel corresponding to the packet flow.
1. A method comprising:
receiving a data packet at a network node;
determining whether the data packet is traveling in a forward direction of a packet flow associated with the data packet or a reverse direction of the packet flow;
prior to transmitting the data packet to a destination of the data packet, determining whether to select a tunnel from multiple available tunnels for the data packet to reach the destination or use a pre-selected tunnel for the data packet to reach the destination, the determining whether to select the tunnel from multiple available tunnels or use the pre-selected tunnel being based on whether the data packet is traveling in the forward direction of the packet flow or the reverse direction of the packet flow, wherein the pre-selected tunnel is associated with the packet flow; and
transmitting the data packet through one of the pre-selected tunnel or the selected tunnel from the multiple available tunnels.
2. The method of claim 1 , further comprising responsive to a determination that the received data packet cannot be transmitted through the pre-selected tunnel corresponding to the packet flow, transmitting the data packet in accordance with a routing rule for the data packet.
3. The method of claim 1 , further comprising:
based on a determination that the data packet is traveling in the forward direction of the packet flow, selecting the tunnel from multiple available tunnels; and
transmitting the data packet through the selected tunnel from the multiple available tunnels.
4. The method of claim 1 , wherein the network node includes a router.
5. The method of claim 4 , wherein the router is one of a provider edge router or a customer edge router.
6. The method of claim 1 , further comprising:
based on a determination that the data packet is traveling in the reverse direction of the packet flow, determining to use the pre-selected tunnel for the data packet; and
transmitting the data packet through the pre-selected tunnel.
7. A non-transitory computer-readable storage media storing thereon instructions that, in response to execution by one or more processors, causes the one or more processors to: receive a data packet at a network node; determine whether the data packet is traveling in a forward direction of a packet flow associated with the data packet or a reverse direction of the packet flow; prior to transmitting the data packet to a destination of the data packet, determine whether to select a tunnel from multiple available tunnels for the data packet to reach the destination or use a pre-selected tunnel for the data packet to reach the destination, the determining whether to select the tunnel from multiple available tunnels or use the pre-selected tunnel being based on whether the data packet is traveling in the forward direction of the packet flow or the reverse direction of the packet flow, wherein the pre-selected tunnel is associated with the packet flow; and transmit the data packet through one of the pre-selected tunnel or the selected tunnel from the multiple available tunnels.
8. The method of claim 1 , wherein the packet flow is identified by a source IP address, a destination IP address, a source port number, a destination port number, and a transport protocol indicator.
9. A network node comprising: one or more processors; and a non-transitory computer readable memory storing instructions which, when executed by the one or more processors, cause the one or more processors to: receive a data packet at a network node; determine whether the data packet is traveling in a forward direction of a packet flow associated with the data packet or a reverse direction of the packet flow; prior to transmitting the data packet to a destination of the data packet, determine whether to select a tunnel from multiple available tunnels for the data packet to reach the destination or use a pre-selected tunnel for the data packet to reach the destination, the determining whether to select the tunnel from multiple available tunnels or use the pre- selected tunnel being based on whether the data packet is traveling in the forward direction of the packet flow or the reverse direction of the packet flow, wherein the pre- selected tunnel is associated with the packet flow; and transmit the data packet through one of the pre-selected tunnel or the selected tunnel from the multiple available tunnels.
10. The network node of claim 9 , wherein the instructions, when executed by the one or more processors, cause the one or more processors to transmit, responsive to a determination that the received data packet cannot be transmitted through the pre-selected tunnel corresponding to the packet flow, the data packet in accordance with a routing rule for the data packet.
11. The network node of claim 9 , wherein the packet flow is identified by a source IP address, a destination IP address, a source port number, a destination port number, and a transport protocol indicator. wherein the instructions, when executed by the one or more processors, cause the one or more processors to: select, based on a determination that the data packet is traveling in the forward direction of the packet flow, the tunnel from multiple available tunnels; and transmit the data packet through the selected tunnel from the multiple available tunnels.
12. The network node of claim 9 , wherein the network node includes a router.
13. The network node of claim 12 , wherein the router is one of a provider edge router or a customer edge router.
14. The network node of claim 9 , wherein the instructions, when executed by the one or more processors, cause the one or more processors to: based on a determination that the data packet is traveling in the reverse direction of the packet flow, determine to use the pre-selected tunnel for the data packet; and transmit the data packet through the pre-selected tunnel.
15. The non-transitory computer-readable storage media of claim 7 , wherein the instructions, when executed by the one or more processors, cause the one or more processors to: based on a determination that the data packet is traveling in the reverse direction of the packet flow, determine to use the pre-selected tunnel for the data packet; and transmit the data packet through the pre-selected tunnel.
16. The non-transitory computer-readable storage media of claim 7 , wherein the instructions, when executed by the one or more processors, cause the one or more processors to transmit,, transmit the data packet in accordance with a routing rule for the data packet.
17. The non-transitory computer-readable storage media of claim 7 , wherein the packet flow is identified by a source IP address, a destination IP address, a source port number, a destination port number, and a transport protocol indicator.
18. The non-transitory computer-readable storage media of claim 7 , wherein the network node includes a router.
19. The non-transitory computer-readable storage media of claim 18 , wherein the router is one of a provider edge router or a customer edge router.
20. The non-transitory computer-readable storage media of claim 7 , wherein the instructions, when executed by the one or more processors, cause the one or more processors to: based on a determination that the data packet is traveling in the forward direction of the packet flow, selecting the tunnel from multiple available tunnels; and transmit the data packet through the selected tunnel from the multiple available tunnels.