DETAILED ACTION
Claims 1-20 are pending.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1, 2, 5-10, 13-16 and 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over You et al. (US 2016/0014024 A1) in view of Moreno et al. (US 2013/0182604 A1).
With respect to claim 1, You discloses: a method,
the method comprising the second network device (i.e., CPU and machine readable instructions in memory in You, ¶0013): receiving on a port of a CPU (central processing unit) of the second network device a packet from the first network device destined for a host connected to the second network device (i.e., a physical forwarding chip receives a packet and sends it through an output interface to a virtual forwarding unit implemented on a CPU/core in You, ¶0012; ¶0013);
in response to the CPU receiving the packet, initiating an ARP (Address Resolution Protocol) session in the second network device to discover a MAC (media access control) address associated with a DIP (destination Internet protocol) address contained in the packet, wherein the DIP address is an IP address of the host (i.e., the network device learns a destination VM MAC via ARP, creates an ARP entry/host route, and uses the ARP index to retrieve the MAC for the destination IP in You, ¶0003; ¶0023; ¶0058);
storing the discovered MAC address in an entry of a rewrite table of the second network device (i.e., learned MAC information is stored with host routes/ARP entries in forwarding tables, including a host FIB entry, ARP index, next-hop, and MAC address in You, ¶0053; ¶0054); and
advertising routing information to one or more of the plurality of network devices, the routing information comprising a host route that specifies a full IP address of the host, an identifier of an egress pipeline associated with a physical port on the second network device to which the host is connected (i.e., the host route/routing information sent for storage includes the destination IP host prefix, ARP index, MAC/ARP entry, and next-hop output interface/port in You, ¶0059; ¶0060; ¶0061), and
an index of the entry in the rewrite table where the discovered MAC address is stored (i.e., each host FIB entry includes an ARP index that points to the ARP/MAC entry used for the discovered destination MAC in You, ¶0054; ¶0058; ¶0061); and
subsequent to advertising the routing information, receiving subsequent packets from the first network device, destined for the host, on the egress pipeline and not on the CPU port, wherein the packets are processed in the egress pipeline. (i.e., after a host route is installed in the physical chip, packets matching the destination are fast-forwarded by the physical chip rather than sent to the virtual/CPU path in You, ¶0042; ¶0062; ¶0074).
You discloses a physical forwarding chip plus CPU-implemented virtual forwarding unit: first packets can follow a subnet route to CPU/software, and learned host routes can later control forwarding (¶0013; ¶0014). You do(es) not explicitly disclose the following. Moreno, in order to improves scaling and service quality by reducing flooding and using core/spine switches to relay between edge devices (¶0018; ¶0030, and ¶0044), discloses:
in an Ethernet fabric comprising a plurality of network devices including a first network device and a second network device (i.e., a large Layer-2 Ethernet/FabricPath/TRILL fabric in which switches forward by MAC address and map host addresses to switch identifiers in Moreno, ¶0002; ¶0003).
Based on You in view of Moreno, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize the teachings of Moreno to improve upon those of You in order to improves scaling and service quality by reducing flooding and using core/spine switches to relay between edge devices.
With respect to claim 2, You discloses: the method of claim 1, wherein the MAC address of the host is unknown at the time of receiving the packet from the first network device, wherein the MAC address of the host is known at the time of receiving the subsequent packets from the first network device (i.e., subsequent packets carry the same destination IP; the physical or virtual forwarding unit matches that destination IP to the now-known host route in You, ¶0030; ¶0058; ¶0074).
With respect to claim 5, You discloses: the method of claim 1, wherein the IP address is an IPv4 address and the connected route is a /n prefix, where 'n' is less than 32 (i.e., the IPv4 example uses a subnet route with /24 prefix while host routes use /32 in You, ¶0020; ¶0027; ¶0056).
With respect to claim 6, You discloses: the method of claim 1, wherein the IP address is an IPv6 address and the connected route is a /n prefix, where 'n' is less than 128 (i.e., the same host/subnet route technique applies to IPv6 as well as IPv4; /24 prefix route is less than 128 in You, ¶0054; ¶0056; ¶0076).
With respect to claim 7, You discloses a physical forwarding chip plus CPU-implemented virtual forwarding unit: first packets can follow a subnet route to CPU/software, and learned host routes can later control forwarding (¶0013; ¶0014). You do(es) not explicitly disclose the following. Moreno, in order to improves scaling and service quality by reducing flooding and using core/spine switches to relay between edge devices (¶0018; ¶0030, and ¶0044), discloses: the method of claim 1, wherein a network device among the plurality of network devices that receives the routing information associates the host route with the identifier of the egress pipeline associated with the physical port on the second network device to which the host is connected (i.e., advertised routing/address information is learned by peer devices and associated with the host, including host MAC reachable via a switch ID. in Moreno, ¶0038; ¶0040).
Based on You in view of Moreno, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize the teachings of Moreno to improve upon those of You in order to improves scaling and service quality by reducing flooding and using core/spine switches to relay between edge devices.
With respect to claim 8, You discloses a physical forwarding chip plus CPU-implemented virtual forwarding unit: first packets can follow a subnet route to CPU/software, and learned host routes can later control forwarding (¶0013; ¶0014). You do(es) not explicitly disclose the following. Moreno, in order to improves scaling and service quality by reducing flooding and using core/spine switches to relay between edge devices (¶0018; ¶0030, and ¶0044), discloses: the method of claim 1, wherein the Ethernet fabric further comprises a plurality of spine devices that interconnect the plurality of network devices, wherein the packet is sent by the first network device to at least one spine device, wherein the at least one spine device sends the packet to the CPU port of the second network device (i.e., the fabric includes core/intermediate switches between routers/edge switches; core switches correspond to a spine between devices in Moreno, ¶0027; ¶0029; ¶0034).
Based on You in view of Moreno, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize the teachings of Moreno to improve upon those of You in order to improves scaling and service quality by reducing flooding and using core/spine switches to relay between edge devices.
With respect to claim 9, the limitation(s) of claim 9 are similar to those of claim(s) 1. Therefore, claim 9 is rejected with the same reasoning as claim(s) 1.
With respect to claim 10, the limitation(s) of claim 10 are similar to those of claim(s) 2. Therefore, claim 10 is rejected with the same reasoning as claim(s) 2.
With respect to claim 13, the limitation(s) of claim 13 are similar to those of claim(s) 5. Therefore, claim 13 is rejected with the same reasoning as claim(s) 5.
With respect to claim 14, the limitation(s) of claim 14 are similar to those of claim(s) 6. Therefore, claim 14 is rejected with the same reasoning as claim(s) 6.
With respect to claim 15, the limitation(s) of claim 15 are similar to those of claim(s) 1. Therefore, claim 15 is rejected with the same reasoning as claim(s) 1.
With respect to claim 16, the limitation(s) of claim 16 are similar to those of claim(s) 2. Therefore, claim 16 is rejected with the same reasoning as claim(s) 2.
With respect to claim 19, the limitation(s) of claim 19 are similar to those of claim(s) 5. Therefore, claim 19 is rejected with the same reasoning as claim(s) 5.
With respect to claim 20, the limitation(s) of claim 20 are similar to those of claim(s) 6. Therefore, claim 20 is rejected with the same reasoning as claim(s) 6.
Claim(s) 3, 11, and 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over You et al. (US 2016/0014024 A1) in view of Moreno et al. (US 2013/0182604 A1), and further in view of Yadav et al. (US 2008/0084888 A1).
With respect to claim 3, You discloses a physical forwarding chip plus CPU-implemented virtual forwarding unit: first packets can follow a subnet route to CPU/software, and learned host routes can later control forwarding (¶0013; ¶0014). You and Moreno do(es) not explicitly disclose the following. Yadav, in order to improve conservation of resources and route integrity by preventing route aging due to silent or moved hosts (¶0047, ¶0079), discloses: the method of claim 1, wherein the host is a silent host (i.e., silent-host support uses host tracking/ARP probes to maintain or remove host-route associations when a host may not generate traffic in Yadav, ¶0047; ¶0079).
Based on You in view of Moreno, and further in view of Yadav, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize the teachings of Yadav to improve upon those of You in order to improve conservation of resources and route integrity by preventing route aging due to silent or moved hosts.
With respect to claim 11, the limitation(s) of claim 11 are similar to those of claim(s) 3. Therefore, claim 11 is rejected with the same reasoning as claim(s) 3.
With respect to claim 17, the limitation(s) of claim 17 are similar to those of claim(s) 3. Therefore, claim 17 is rejected with the same reasoning as claim(s) 3.
Claim(s) 4, 12, and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over You et al. (US 2016/0014024 A1) in view of Moreno et al. (US 2013/0182604 A1), and further in view of Keesara et al. (US 2014/0229631 A1).
With respect to claim 4, You discloses: the method of claim 1 (i.e., receiving packets, sending unmatched subnet traffic to CPU/virtual forwarding, and forwarding based on a learned host route in You, ¶0012; ¶0013; ¶0014), further comprising prior to receiving the packet from the first network device:
configuring the physical port on the second network device with a connected route that represents a network portion of the IP address of the host (i.e., an initial subnet route for a network-IP portion such as 1.1.1.0/24 is configured so its output interface points to the CPU/virtual forwarding path in You, ¶0026; ¶0027; ¶0055; ¶0056),
wherein the packet from the first network device is received on the CPU port of the second network device by virtue of the first network device receiving and using the initial routing information (i.e., the packet is received on the CPU/virtual path because the physical chip uses the initial subnet route’s output interface to reach the virtual forwarding unit in You, ¶0032; ¶0057).
You discloses the subnet route is modified/sent so its output interface is the port connecting the physical forwarding chip to the virtual/CPU forwarding path (¶0026; ¶0027). You and Moreno do(es) not explicitly disclose the following. Keesara, in order to improve connectivity by advertising fallback reachability prior to ARP learning (¶0022, ¶0023), discloses:
advertising initial routing information to the plurality of network devices, the initial routing information comprising the connected route and an identifier of the CPU port of the second network device (i.e., advertises an initial subnet network route before a host-specific ARP/host route is learned and advertised in Keesara, ¶0021; ¶0023; ¶0030).
Based on You in view of Moreno, and further in view of Keesara, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize the teachings of Keesara to improve upon those of You in order to improve connectivity by advertising fallback reachability prior to ARP learning.
With respect to claim 12, the limitation(s) of claim 12 are similar to those of claim(s) 4. Therefore, claim 12 is rejected with the same reasoning as claim(s) 4.
With respect to claim 18, the limitation(s) of claim 18 are similar to those of claim(s) 4. Therefore, claim 18 is rejected with the same reasoning as claim(s) 4.
Conclusion
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Sherman Lin
7/20/2026
/S. L./Examiner, Art Unit 2447
/JOON H HWANG/Supervisory Patent Examiner, Art Unit 2447
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