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Date: Wed, 10 Aug 2022 16:26:34 -0500
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Subject: Re: postgresql definitive list of network resources used/needed?
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From: Ron <ronljohnsonjr@gmail.com>
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On 8/10/22 16:08, richard coleman wrote:
> I'm currently standing up a number of PostgreSQL 14 servers.  There is a 
> question concerning ports and protocols required or used by PostgreSQL.  
> Unfortunately, I can't seem to find any such listing.  Most references 
> only mention the primary connection port, ex: tcp 5432.
>
> Apparently, I've discovered that PostgreSQL connects to itself over UDP.  
> I've also discovered, while looking at the network while one of our server 
> was running PostgreSQL, that while there were a number of connections 
> between local 5432 and a random remote port,

That's how TCP IP works; you see the same with ssh, http, dns, etc, etc.

> there was also a connection from a local random port to a remote 5432.

A local process connecting to a remote postgresql database.

>   If these ports were closed and only 5432 left open, this connection 
> would have failed.
>
> Does anyone know where I might find the definitive listing of ports and 
> protocols used by PostgreSQL?

I'm pretty sure I only ever requuest that TCP 5432 be opened in the 
firewall, and that as incoming to the DB server.

-- 
Angular momentum makes the world go 'round.