Should low port peers be blocked?

[ciaobaby]

It's not that they ARE 'dangerous', it's simply that the 'low' ports are mostly reserved for specific services and a swarm "might" be used to vector an DDoS attack to a remote mail server (25, 110, 143) or a remote web server (80, 443).

[potska]

I know that one ISP has only port 113 open and all other are closed and even cannot be opened by request from ISP. Friend who uses that ISP is glad that even one port is open so he can use it if needed.

About 10 years back my ISP had exactly same system, now all ports are opened.