Does My Internet Service Provider Block Port 80?

If you are like me who runs a little web server at home, you may encounter this problem, that is, regardless how you try, you simply cannot get port forwarding to work for port 80 while port forwarding functions fine for any other ports at home. It turns out that I am not alone. For instance, this Linux Questions thread states,

"Turns out Cablevision (my provider) 'blocks' port forwarding on their routers, so they say."

Yes, and indeed, that is what they say. My current Internet Service Provider (ISP) is Optimum. It states on their customer service site,

"Because Port 80 is often used by malicious software, including viruses and worms, Optimum, like many ISPs (Internet Service Providers), blocks this port for all standard Optimum customers."

Fortunately, it also provides a solution in the same page,

"

1. Go to www.optimum.net.
2. Sign in with your Optimum ID and password
3. Place your cursor on and click the 'Internet' header
4. Under 'Port Configuration' click on 'Settings'
5. Under Port 80, click on the slider to turn On or turn Off.

"

This post serves as a reminder that you may want to check with your ISP if you struggle to get port forwarding to work for port 80 at home, and it may save you a few hours.