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Re: Changing ports.

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  • Subject: Re: Changing ports.
  • Date: Tue, 14 Jun 2005 13:15:58 -0600
Stonie,

>Date: Tue, 14 Jun 2005 12:18:45 +0000
>From: "Stonie R. Cooper" <address@hidden>
>To: Steve Emmerson <address@hidden>
>Subject: Changing ports.

The above message contained the following:

> Steve - I apologize for the bother - but I have hit upon an issue I
> am unsure the resolution.  The standard port for LDM is 388, unless
> portmapper is used to assign some other port.

Not quite.  The "well known" port for the LDM is 388.  The LDM server,
rpc.ldmd, must be run by root (or be setuid and owned by root) in order
to obtain this port.  If the server can't get that port, then it will
get an arbitrary port from the operating system -- in which case it must
register with the portmapper so that other LDM-s can learn what port to
use.

> I have a security case
> where portmapper cannot be used, but I need to make LDM use something
> other than 388 - say 3105.  How does one one go about:

Why can't the LDM server use port 388?  This is tantamount to not
allowing the mail server to use port 25.

>  - setting the server side (listening side) to a different port;
>  - then getting the client side to request on that different port for a 
> "request"?

The "well known" port number 388 is compiled-into the LDM server.  In
order to have a downstream LDM connect to a different port on the
upstream host, it would be necessary to change the "388" in file
"config/ldmconfig.h" to the appropriate value and then rebuild the LDM
server.  Another LDM wouldn't be able to connect to that downstream LDM
unless it, too, was rebuilt to use the other port number (and so on).

> Stonie Cooper,
> Planetary Data, Incorporated
> (402) 727-6599

Regards,
Steve Emmerson