Services or Wesbite that Check open and closed ports all at once?

[NoiselessOwl 26]

I remember there is a old GRC ShieldsUp! scans for open and closed port. And it provide a visual data of which port is open and closed. I am wondering if there is a current website or services that do similar what GRC ShieldsUp did. I know there is a few website but I have to pick one port number for it to scan than scanning all over together once. I am not sure how current GRC port scan is because I remember it 10 or 15 years ago and I imagine new tech have different approach to handle the ports. I am asking this because I know my college have some ports blocked. I don't want to go through OpenVPN cert from my phone to find which one is blocked. I did check my college policy with VPN, and they are fine with it as long I am not violating their term and condition and doing illegal activity. 

[zhang888 1066]

You can download nmap (https://nmap.org) and scan one of the Air servers on ports 1-2018.

The ports you will see as "open" are most likely OK from your network.

 

Note that this may violate another policy, i.e. no port scanning/security testing from inside the network.