Hey dude, I don't think some words can find the problem. You can send your config file or some printscreens to the Supporter of TP-Link and maybe they can help you.

Hey dude, you mean you can not login the Web GUI? Generally, I will make sure the address is correct and then clean the cache in the browser. You can have a try.

The SG1008D is a plug and play device. Each port should be OK. There is no different between them.

Does this issue happen suddenly? Or the first time you use?

Is that your topology like this "600VPN---ISP Modem---Internet"? You set an static IP which is in the same range of the modem for 600VPN. Have you ever PING from the LAN of 600VPN to the ISP Modem...

Hi dude...That's normal. When you ping a device in the switch, the data will be sent by the hardware. However when you ping the Manage IP of the switch, the traffic will be transmitted through the...