Re: network adapters, IP addresses, ports, domain names

["Jonathan A. Kollasch" <jakllsch%kollasch.net@localhost>]

On Thu, Nov 16, 2023 at 04:18:48PM +0000, Steve Blinkhorn wrote:
> You wrote:
> > 
> > On Thu, Nov 16, 2023 at 03:48:49PM +0000, Steve Blinkhorn wrote:
> > > In a situation where a NetBSD machine (9.2 amd64 if it matters) has
> > > multiple network adapters each with multiple IP addresses
> > > corresponding to diverse domain names, to what are port numbers
> > > uniquely attached?
> > > 
> > 
> > They're attached to IP addresses, either specific IP addresses or
> > unspecified IP address (0.0.0.0 or ::).  If the server application
> > binds to the unspecified IP address the port is not bindable to specific
> > IP addresses by other servers.
> > 
> 
> So can two different IP addresses on the same adapter each use the same
> port number each for its own distinct purposes?  I would assume they
> can since I run different web servers that use ports 80 and 443 in
> this way.   (Obviously I have a debugging problem that's irking me,
> but I think is not strictly a NetBSD issue - I'm just trying to
> eliminate wilder possible sources).

Yes, that's the idea.