Renaud & I were wondering what the best list of ports for TCP ping
could be.
When a machine is not firewalled, it doesn't matter. Otherwise:
- 80 is often open, but it may be disturbed by transparent proxys.
- 22, 25, 443 are also good candidates
- 113 is even better, because it either properly rejected by the
firewall, or allowed.
But if the firewall rejects connections on port 113 for all
addresses, we'll see all the IP range "up".
There is no simple solution. But what the best default could be?
- 80;443;25
- 113;80;25
- 80 (former default)
Anything else?
could be.
When a machine is not firewalled, it doesn't matter. Otherwise:
- 80 is often open, but it may be disturbed by transparent proxys.
- 22, 25, 443 are also good candidates
- 113 is even better, because it either properly rejected by the
firewall, or allowed.
But if the firewall rejects connections on port 113 for all
addresses, we'll see all the IP range "up".
There is no simple solution. But what the best default could be?
- 80;443;25
- 113;80;25
- 80 (former default)
Anything else?