SOFTWARE FIB ARP FEC ENCODING

• US 20170070431A1
• Filed: 08/23/2016
• Published: 03/09/2017
• Est. Priority Date: 09/04/2015
• Status: Active Grant

• Current Assignee: Arista Networks, Inc.
• Original Assignee: Arista Networks, Inc.
• Inventors: Nidumolu, Kalyan, Bhatia, Navdeep
• Granted Patent: US 10,530,692 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 45/38 Flow based routing
• CPC Class Codes: H04L 45/54 Organization of routing tables
• CPC Class Codes: H04L 45/66 Layer 2 routing, e.g. in Ethernet based MAN's
• CPC Class Codes: H04L 45/741 Routing in networks with a plurality of addressing schemes, e.g. with both IPv4 and IPv6
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 45/7452 Multiple parallel or consecutive lookup operations lookup operation involving Bloom filters H04L45/7459

Abstract

Described herein are various embodiments of a network element to process routing entries in a forwarding information base (FIB) for hosts that are directly attached to a multi-layer network element to encode address resolution protocol (ARP) data into forwarding equivalence class (FEC) entries for the directly attached hosts. One embodiment provides for a network element comprising a control plane including a forwarding agent and a data plane coupled to the control plane. The data plane can include a forwarding engine to forward a unit of network data from an ingress interface to an egress interface. The forwarding agent can be configured to program the forwarding engine with a forwarding information base having data-link layer forwarding data encoded into a network-layer forwarding entry.

Claims

1. A network element comprising:

a control plane including a forwarding agent;

a data plane coupled to the control plane, the data plane including a forwarding engine to forward a unit of network data from an ingress interface to an egress interface, wherein the forwarding agent is to program the forwarding engine with a forwarding information base having data-link layer forwarding data encoded into a network-layer forwarding entry.

2. The network element as in claim 1, wherein the data-link layer forwarding data is derived from an address resolution protocol table.

3. The network element as in claim 1, wherein the network-layer forwarding entry is a forwarding equivalence class (FEC) entry.

4. The network element as in claim 3, wherein the forwarding equivalence class entry is associated with a specific virtual local area network (VLAN), media access control (MAC) address, and physical port.

5. The network element as in claim 4, wherein the network layer forwarding entry associates an Internet Protocol (IP) prefix with a forwarding equivalence class entry.

6. The network element as in claim 5, wherein the Internet Protocol (IP) prefix is a direct match for an IP address.

7. The network element as in claim 6, wherein the IP prefix is an IPv4/32 prefix.

8. The network element as in claim 6, wherein the IP prefix is an IPv6/128 prefix.

9. The network element as in claim 6, wherein the control plane includes one or more processors and the forwarding agent is to cause the one or more processors to:

derive an IP address from the prefix;

derive an Ethernet address from the IP address and a VLAN ID;

derive a physical port from the VLAN ID and the Ethernet address; and

define a FEC identifier for the combination of the VLAN, Ethernet address and physical port.

10. A non-transitory machine-readable medium storing instructions which, when executed by one or more processors, cause the one or more processors to perform operations comprising:

deriving a layer 3 address from a layer 3 forwarding table entry in a forwarding information base (FIB) of a network element;

deriving a layer 2 address from the layer 3 address and a virtual local area network (VLAN) identifier for a VLAN connected to the network element;

deriving a physical port from the VLAN identifier and the layer 2 address; and

defining a forwarding equivalence class (FEC) entry for the VLAN identifier, layer 2 address, and physical port.

11. The non-transitory machine-readable medium of claim 10, wherein the FIB includes a single FEC entry per VLAN.

12. The non-transitory machine-readable medium of claim 10, including instructions to perform additional operations comprising defining the FEC entry for a specific route type in the FIB.

13. The non-transitory machine-readable medium of claim 12, wherein the specific route type is an attached route type, the attached route type specified as a route type for a directly attached host of the network element.

14. The non-transitory machine-readable medium of claim 13, wherein the directly attached host of the network has a route specified by an IPv4/32 prefix.

15. The non-transitory machine-readable medium of claim 13, wherein the directly attached host of the network has a route specified by an IPv6/128 prefix.

16. The non-transitory machine-readable medium of claim 13, further comprising instructions to perform additional operations comprising:

creating an updated FIB by mapping each attached route in the FIB to a corresponding FEC entry; and

programming a forwarding engine of the network element with the updated FIB.

17. A method of configuring a forwarding engine of a network element, the method comprising:

deriving a layer 3 address from a layer 3 forwarding table entry in a forwarding information base (FIB) of the network element;

deriving a layer 2 address from the layer 3 address and a virtual local area network (VLAN) identifier for a VLAN connected to the network element;

deriving a physical port from the VLAN identifier and the layer 2 address; and

defining a forwarding equivalence class (FEC) entry for the VLAN identifier, layer 2 address, and physical port.

18. The method as in claim 17, further comprising deriving a forwarding equivalence class entry for each forwarding entry in the forwarding information base (FIB) of the network element that specifies a directly attached host, the directly attached host having an forwarding entry specifying an IPv4/32 prefix or an IPv6/128 prefix.

19. The method as in claim 18, further comprising:

creating an updated FIB by mapping the forwarding entry for each directly attached host to a corresponding FEC entry; and

programming the forwarding engine of the network element with the updated FIB.

20. The method as in claim 19, wherein the FIB includes a single FEC entry per VLAN.