Provisional modes for multi-mode network devices
Techniques for implementing a provisional mode in a multi-mode network device (i.e., a network device that supports at least first and second modes of operation) are provided. According to one embodiment, the network device can receive, while running in the first mode, a request to enter the second mode. In response to the request, the network device can enter a third mode that is a provisional version of the second mode. Then, while running in the third mode, the network device can accept one or more configuration commands or settings for the second mode while simultaneously processing live network traffic according to the first mode.
1. A method performed by a network device that supports a first mode of operation and a second mode of operation, the method comprising:
receiving, by the network device while running in the first mode, a request to enter the second mode;
in response to the request, entering, by the network device, a third mode that is a provisional version of the second mode; and
while running in the third mode, accepting, by the network device, one or more configuration commands or settings for the second mode while simultaneously processing live network traffic according to the first mode,
wherein the accepting of the one or more configuration commands or settings for the second mode does not cause any changes to the network device's runtime operation until the network device is reloaded to run in the second mode via a user-provided command.
2. The method of claim 1 further comprising, while running in the third mode:
validating the one or more configuration commands or settings according to one or more rules that are applicable to the second mode.
3. The method of claim 1 further comprising, while running in the third mode:
saving the one or more configuration commands or settings for the second mode to a nonvolatile memory, without applying the one or more configuration commands or settings to any operational data structures of the network device.
4. The method of claim 1 further comprising, while running in the third mode:
exposing a configuration user interface that is substantially similar to the second mode, the configuration user interface being operable for receiving the one or more configuration commands or settings for the second mode from a user.
5. The method of claim 1 further comprising, while running in the third mode:
blocking any configuration commands or settings for the first mode.
6. The method of claim 1 further comprising, while running in the third mode:
blocking any operational commands or settings for the second mode.
7. The method of claim 1 wherein the network device cannot directly switch over from running in the first mode to running in the second mode.
8. The method of claim 1 wherein the network device can only switch over to running in the second mode while running in the third mode.
9. The method of claim 1 further comprising, upon a reload of the network device:
checking whether a configuration file pertaining to the second mode exists in a nonvolatile memory of the network device; and
if the configuration file does not exist, booting up the network device in the first mode.
10. The method of claim 9 further comprising, if the configuration file does exist:
checking whether the configuration file includes a parameter indicating the request to enter the second mode; and
if the configuration file includes the parameter:
booting up the network device in the second mode; and
operating the network device in accordance with configuration commands or settings included in the configuration file.
11. The method of claim 1 further comprising, while running in the third mode:
receiving a request to exit from the second mode; and
in response to the request to exit from the second mode, entering the first mode without reloading the network device.
12. The method of claim 11 further comprising, prior to entering the first mode:
determining whether a parameter indicating the request to enter the second mode has been saved in a configuration file; and
if the parameter has been saved in the configuration file, removing the parameter from the configuration file.
13. The method of claim 1 further comprising, while running in the third mode:
receiving a request to reload the network device;
in response to the request to reload the network device, checking whether:
a configuration file pertaining to the second mode exists in a nonvolatile memory of the network device; and
a parameter indicating the request to enter the second mode is included in the configuration file.
14. The method of claim 13 wherein if the parameter is not included in the configuration file:
preventing a reload of the network device.
15. The method of claim 1 wherein the first mode is a switch or router mode.
16. The method of claim 1 wherein the second mode is a port extender mode.
17. A non-transitory computer readable storage medium having stored thereon program code executable by a network device that supports a first mode of operation and a second mode of operation, the program code causing the network device to:
receive, while running in the first mode, a request to enter the second mode;
in response to the request, enter a third mode that is a provisional version of the second mode; and
while running in the third mode, accept one or more configuration commands or settings for the second mode while simultaneously processing live network traffic according to the first mode,
wherein the accepting of the one or more configuration commands or settings for the second mode does not cause any changes to the network device's runtime operation until the network device is reloaded to run in the second mode via a user-provided command.
18. A network device comprising:
a processor that supports a first mode of operation and a second mode of operation; and
a non-transitory computer readable medium having stored thereon program code that, when executed by the processor, causes the processor to:
receive, while running in the first mode, a request to enter the second mode;
in response to the request, enter a third mode that is a provisional version of the second mode; and
while running in the third mode, accept one or more configuration commands or settings for the second mode while simultaneously processing live network traffic according to the first mode,
wherein the accepting of the one or more configuration commands or settings for the second mode does not cause any changes to the network device's runtime operation until the network device is reloaded to run in the second mode via a user-provided command.
19. The network device of claim 18 wherein the network device is operable to act as a port extender in an 802.1BR topology.