Updated a couple of switches to this new firmware V1.0.5.21 from 1.0.5.17, and within 72 hours, each switch suddenly failed. Am running multiple VLANs, and all of a sudden the VLANs would stop working. The switch would become inaccessible - (web-browser would not connect) and I'm unable to ping the switch (on it's subnet).
Unplugging the power cable from the Switch for a couple of minutes, and plugging it back in - everything is back to normal and functioning.
Will there be another release coming up to resolve this? - I'll keep this firmware running for a few more days, and the next incident of this hiccup - will have to revert to the previous firmware. I had previous firmwares running for a good 6+ months without a hiccup.
