Leaf-to-spine uplink bandwidth advertisement to leaf-connected servers

1. A method comprising:

receiving, by a server computing device from each leaf network switching device of a plurality of leaf network switching devices to which the server computing device is physically connected, an advertisement indicating uplink bandwidth of the leaf network switching device to each spine network switching device of a plurality of spine network switching devices to which the leaf network switching device is connected;

receiving, by the server computing device from each leaf network switching device, information as to a plurality of other server computing devices collocated at the leaf network switching device;

transmitting, by the server computing device, local network traffic to each other server computing device through one of the leaf network switching devices at which the other server computing device is collocated with the server computing device; and

distributing, by the server computing device, network traffic through the leaf network switching devices to the spine network switching devices based on the uplink bandwidth of each leaf network switching device to each spine network switching device.

2. The method of claim 1 , wherein the leaf network switching devices are not physically connected to one another.

3. The method of claim 1 , further comprising:

detecting, by the server computing device, local bandwidth between the server computing device and each leaf network switching device,

wherein the server computing device distributes the network traffic through the leaf network switching devices to the spine network switching devices further based on the local bandwidth between the server computing device and each leaf network switching device.

4. The method of claim 3 , wherein the server computing device dynamically detects availability of the local bandwidth between the server computing device and each leaf network switching devices, as the availability of the local bandwidth changes.

5. The method of claim 1 , wherein the server computing device dynamically receives the information from each leaf network switching device, as the information changes.

6. The method of claim 1 , further comprising:

transmitting, by the server computing device, local network traffic to a first different server computing device through a first leaf network switching device of the leaf network switching devices at which the first different server computing device is not collocated with the different server computing device;

receiving, by the server computing device from the first leaf network switching device, information that the first different server computing device is not collocated at the first different server computing device; and

responsively transmitting, by the server computing device, further local network traffic to the first different server computing through a second leaf network switching device of the leaf network switching devices.

7. The method of claim 1 , wherein the server computing device dynamically receives the advertisement from each leaf network switching device, as availability of the uplink bandwidth of the leaf network switching device to any spine network switching device changes.

8. A system comprising:

a plurality of spine network switching devices;

a plurality of leaf network switching devices that are not connected to one another, each leaf network switching device connected to each spine network switching device, each leaf network switching device to transmit an advertisement indicating uplink bandwidth to each spine network device; and

a plurality of server computing devices, each server computing device connected to each leaf network switching device, each server computing device to distribute network traffic through the leaf network switching devices to the spine network switching devices based on the uplink bandwidth that the leaf network switching devices advertise; wherein each network switching device is to receive local network traffic from the server computing devices, and responsive to determining that the local network traffic pertains to non-collocated server computing devices, inform the server computing devices that the local network traffic pertains to the non-collocated server computing devices.

9. The system of claim 8 , wherein each server computing device is further to detect local bandwidth between the server computing device and each leaf network switching device,

wherein the server computing device is to distribute the network traffic through the leaf network switching devices to the spine network switching devices further based on the local bandwidth between the server computing device and each leaf network switching device.

10. The system of claim 8 , wherein each leaf network device is further to dynamically transmit information as to the server computing devices collocated at the leaf network switching device, as the information changes,

and wherein each server computing device is further to transmit local network traffic to a different server computing device of the server computing devices through one of the leaf network switching devices at which the different server computing device is collocated with the server computing device.

11. The system of claim 8 , wherein each leaf network switching device is to dynamically transmit the advertisement indicating availability of the uplink bandwidth as the availability of the uplink bandwidth to any spine network switching device changes.

12. The system of claim 8 , wherein server computing device-leaf network switching device communication occurs within a layer two (L2) network, and leaf network switching device-spine network switching device communication occurs within an L2 network,

and wherein each leaf network switching device is a lower-tier network switch, and each spine network switching device is an upper-tier network switch.

13. The system of claim 8 , wherein server computing device-leaf network switching device communication occurs within a layer three (L3) network, and leaf network switching device-spine network switching device communication occurs within a layer two (L2) network,

and wherein each leaf network switching device is a lower-tier network switch, and each spine network switching device is an upper-tier network switch.

14. The system of claim 8 , wherein server computing device-leaf network switching device communication occurs within a layer two (L2) network, and leaf network switching device-spine network switching device occurs within a layer three (L3) network,

and wherein each leaf network switching device is a lower-tier network switch, and each spine network switching device is an upper-tier network switch.

15. A non-transitory computer-readable data storage medium storing program code executable by a leaf network switching device to:

detect uplink bandwidth between the leaf network switching device and each spine network switching device of a plurality of spine network switching devices to which the leaf network switching device is connected and to which a plurality of other leaf network switching devices are connected, wherein the plurality of the other leaf network switching devices are not connected to the leaf network switching device;

transmit an advertisement indicating the uplink bandwidth between the leaf network switching device and each spine network switching device, to each server computing device of a plurality of server computing devices to which the leaf network switching device is connected;

receive network traffic from the server computing devices that is distributed based on the uplink bandwidth between the leaf networking switching device and each spine network switching device indicated in the advertisement sent to each server computing device; and

route the received network traffic to the spine network switching devices.

16. The non-transitory computer-readable data storage medium of claim 15 , wherein the program is code is executable by the leaf network switching device to further:

dynamically transmit to each server computing device information as to the server computing devices collocated at the leaf network, as the information changes, on which basis the server computing devices distribute local network traffic to the leaf network switching device.

17. The non-transitory computer-readable data storage medium of claim 15 , wherein the program is code is executable by the leaf network switching device to further:

receive local network traffic from a source server computing device to which the leaf network switching device is connected;

determine that a destination server computing device of the local network traffic is not connected to the leaf network switching device;

responsively tunneling the local network traffic to the destination server computing device through one of the spine network switching devices to which the leaf network switching device is connected and to which another leaf network switching device connected to the destination server computing device is connected; and

inform the source server computing device that the destination server computing device is not collocated at the leaf network switching device.