`wget` usually works when the network is good. However, disconnection often occurs in areas where the network is not ideal, which will lead to the infeasibility of online upgrade. It is usually necessary to manually download ISO and upload it to vyos, and then perform local upgrade. The feasibility of changing `wget` to `aria2c` is discussed. And ask to modify it.
Using `aria2c`, we can achieve the disconnection retransmission and parallel transmission