SOLVED: External application connections


I am building a PHP application that connects to an external dedicated server from my dreamhost fully hosted site (eg SMTP, SNMP, etc).

I would like to know for certain what IP or subnet (preferrably IP) these connections would come from and if it’s static because I will have to allow them through the external server’s firewall via an IP/subnet:port pinhole.


From Dreamhost Support:

Unfortunately, connections from our servers to other networks are not
guaranteed to be from any specific IP or network (we have just shy of 10
different network ranges), so I’m afraid I cannot really provide you any
specific information in that regard. If you do need to allow connections
through the firewall, you’ll need to use your current connection
technique in PHP to make a request to “” to get
the IP address you’re connecting from and then add that address.

Regretfully, the IP you’re connecting from comes with no assurances that
it would be static, as should any need come, we do reserve the right to
re-number the machines on the fly without any warning at all. (While we
strive to not do this, we have had to do so in the past, and such
circumstances are not such the situation that we can provide any sort of

You may want to set it up to forward from the connecting IP, and then set
up some sort of cron job to check for the IP changing and email you if it
does, so that you can adjust it.

I mean, it’s not that we change it all the time, but I’d rather you be
prepared and have notification systems set up rather than have any
troubles, given that we really cannot provide such notifications in the
even that it does change. :slight_smile: