Hash collision mitigation system
A hash collision mitigation system includes a source device coupled to a destination device by a networking device. The networking device receives a first packet from the source device, and uses first packet information included in the first packet to perform a hash operation on the first packet and generate a hash value. The networking device then determines that the hash value has caused a hash collision with a first hash value forwarding entry in a hash forwarding table in the networking device and, in response, generates a first Policy Based Routing (PBR) entry for the first packet. The first PBR entry is configured to provide for the forwarding of at least one second packet received from the destination device and directed to the source device, and that first PBR is stored in a Ternary Content Addressable Memory (TCAM) in the networking device.
1. A hash-collision-based packet forwarding system, comprising:
a source device;
a destination device; and
a networking device coupling the source device to the destination device, wherein the networking device is configured to:
receive, from the source device, a first packet that is directed to the destination device;
perform, using first packet information included in the first packet, a hash operation to generate a hash value;
determine that the hash value has caused a hash collision with a first hash value forwarding entry in a hash forwarding table in the networking device;
generate, in response to determining that the hash value has caused a hash collision, a first Policy Based Routing (PBR) entry for the first packet, wherein the first PBR entry is configured to provide for the forwarding of at least one second packet received from the destination device and directed to the source device; and
store the first PBR entry in a Ternary Content Addressable Memory (TCAM) in the networking device.
2. The system of claim 1 , wherein the first PBR entry is stored in a Layer 2 (L2) area of the TCAM in a lower priority position relative to a plurality of second PBR entries that were previously stored in the L2 area of the TCAM.
3. The system of claim 2 , wherein the networking device is configured to:
generate a second PBR entry that is configured to provide for the aging of an address that is associated with the source device and that is included in the first PBR entry; and
store the second PBR entry in the L2 area of the TCAM in a lower priority position relative to the first PBR entry.
4. The system of claim 3 , wherein the networking device is configured to:
generate a third PBR entry that is configured to provide for the movement of the address that is associated with the source device and that is included in the first PBR entry; and
store the third PBR entry in the L2 area of the TCAM in a lower priority position relative to the second PBR entry.
5. The system of claim 1 , wherein the first PBR entry is stored in a Layer 3 (L3) area of the TCAM in a lower priority position relative to a plurality of second PBR entries that were previously stored in the L3 area of the TCAM.
6. The system of claim 1 , wherein the networking device is configured to:
determine that the first hash value forwarding entry associated with the hash collision has been removed from the hash forwarding table in the networking device;
generate, in response to determining that the first hash value forwarding entry has been removed from the hash forwarding table, a second hash value forwarding entry corresponding to the first PBR entry; and
store the second hash value forwarding entry in the hash forwarding table.
7. An Information Handling System (IHS), comprising:
a processing system; and
a memory system that is coupled to the processing system and that includes instructions that, when executed by the processing system, cause the processing system to provide a switch engine that is configured to:
receive, from a source device, a first packet;
perform, using first packet information included in the first packet, a hash operation to generate a hash value;
determine that the hash value has caused a hash collision with a first hash value forwarding entry in a hash forwarding table;
generate, in response to determining that the hash value has caused a hash collision, a first Policy Based Routing (PBR) entry for the first packet, wherein the first PBR entry is configured to provide for the forwarding of at least one second packet directed to the source device; and
store the first PBR entry in a Ternary Content Addressable Memory (TCAM).
8. The IHS of claim 7 , wherein the first PBR entry is stored in a Layer 2 (L2) area of the TCAM in a lower priority position relative to a plurality of second PBR entries that were previously stored in the L2 area of the TCAM.
9. The IHS of claim 8 , wherein the switch engine is configured to:
generate a second PBR entry that is configured to provide for the aging of an address that is associated with the source device and that is included in the first PBR entry; and
store the second PBR entry in the L2 area of the TCAM in a lower priority position relative to the first PBR entry.
10. The IHS of claim 9 , wherein the switch engine is configured to:
generate a third PBR entry that is configured to provide for the movement of the address that is associated with the source device and that is included in the first PBR entry; and
store the third PBR entry in the L2 area of the TCAM in a lower priority position relative to the second PBR entry.
11. The IHS of claim 7 , wherein the first PBR entry is stored in a Layer 3 (L3) area of the TCAM in a lower priority position relative to a plurality of second PBR entries that were previously stored in the L3 area of the TCAM.
12. The IHS of claim 7 , wherein the switch engine is configured to:
determine that the first hash value forwarding entry associated with the hash collision has been removed from the hash forwarding table;
generate, in response to determining that the first hash value forwarding entry has been removed from the hash forwarding table, a second hash value forwarding entry corresponding to the first PBR entry; and
store the second hash value forwarding entry in the hash forwarding table.
13. The IHS of claim 7 , wherein the switch engine is configured to:
receive, subsequent to storing the first PBR entry in the TCAM, a second packet;
perform, using second packet information included in the second packet, the hash operation and, in response, generating the hash value; and
forward, in response to generating the hash value via the performance of the hash operation on the second packet, the second packet using the first PBR entry.
14. A method for packet forwarding based on a hash collision, comprising:
receiving, by a networking device from a source device, a first packet;
performing, by the networking device using first packet information included in the first packet, a hash operation to generate a hash value;
determining, by the networking device, that the hash value has caused a hash collision with a first hash value forwarding entry in a hash forwarding table;
generating, by the networking device in response to determining that the hash value has caused a hash collision, a first Policy Based Routing (PBR) entry for the first packet, wherein the first PBR entry is configured to provide for the forwarding of at least one second packet directed to the source device; and
storing, by the networking device, the first PBR entry in a Ternary Content Addressable Memory (TCAM) in the networking device.
15. The method of claim 14 , wherein the first PBR entry is stored in a Layer 2 (L2) area of the TCAM in a lower priority position relative to a plurality of second PBR entries that were previously stored in the L2 area of the TCAM.
16. The method of claim 15 , further comprising:
generating, by the networking device, a second PBR entry that is configured to provide for the aging of an address that is associated with the source device and that is included in the first PBR entry; and
storing, by the networking device, the second PBR entry in the L2 area of the TCAM in a lower priority position relative to the first PBR entry.
17. The method of claim 16 , further comprising:
generating, by the networking device, a third PBR entry that is configured to provide for the movement of the address that is associated with the source device and that is included in the first PBR entry; and
storing, by the networking device, the second PBR entry in the L2 area of the TCAM in a lower priority position relative to the second PBR entry.
18. The method of claim 14 , wherein the first PBR entry is stored in a Layer 3 (L3) area of the TCAM in a lower priority position relative to a plurality of second PBR entries that were previously stored in the L3 area of the TCAM.
19. The method of claim 14 , further comprising:
determining, by the networking device, that the first hash value forwarding entry associated with the hash collision has been removed from the hash forwarding table;
generating, by the networking device in response to determining that the first hash value forwarding entry has been removed from the hash forwarding table, a second hash value forwarding entry corresponding to the first PBR entry; and
storing, by the networking device, the second hash value forwarding entry in the hash forwarding table.
20. The method of claim 14 , further comprising:
receiving, by the networking device subsequent to storing the first PBR entry in the TCAM, a second packet;
performing, by the networking device using second packet information included in the second packet, the hash operation and, in response, generating the hash value; and
forwarding, by the networking device in response to generating the hash value via the performance of the hash operation on the second packet, the second packet using the first PBR entry.