What means port_modify?

[ZackyYoung]

What means switch ports change states? How many states are there, and what changes they correspond to the graph?

[EricLee543]

Currently, our test cases do not cover scenarios related to port modification. However, the project documentation encourages you to implement a complex test case to validate robustness. You can write a function to handle port modification. The port can have states of "up" and "down." If you want to trigger this event, you can enter the following command in the Mininet CLI: sh ovs-ofctl mod-port s1 1 down. This command will disable port 1 of the s1 switch.