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Re: Getting LDM on plane to receive via UCAR RAS and PPP

Janet,

This might also be a TCP wrapper (hosts.allow) line for portmap access;

portmap:        128.117.

Steve is right that using port 388 is better (ie rpc.ldmd suid root).

mike

On Jun 29, 10:44am, Steve Emmerson wrote:
> Subject: Re: Getting LDM on plane to receive via UCAR RAS and PPP
> Janet,
>
> >Date: Wed, 29 Jun 2005 09:28:30 -0600
> >From: Janet Scannell <address@hidden>
> >Organization: UCAR/EOL
> >To: Steve Emmerson <address@hidden>
> >Subject: Re: Getting LDM on plane to receive via UCAR RAS and PPP
>
> The above message contained the following:
>
> > A few more questions about the firewall problems that I am having on
> > linus.
> > rpcinfo -p linus  shows:
> >     300029    6   tcp  46579  ldm
> >     300029    5   tcp  46579  ldm
>
> The above means that an LDM server (RPC program 300029) is running on
> Linus.  It is listening on port 46579 (not what you want) and
> supports versions 5 and 6 of the LDM protocol.
>
> Because the LDM server isn't listening on the well-known LDM port, 388,
> other LDM-related programs will have to connect first to the
> portmapper daemon on Linus (e.g., bind(1)) in order to discover what
> port the LDM server is using.
>
> It is likely that the reason that the LDM server isn't listening on the
> well-known LDM port, 388, is because the LDM program, $HOME/bin/rpc.ldmd,
> is NOT owned by root and has the setuid bit set, i.e., it is not like
> the following:
>
>     $ ls -l /local/ldm/bin/rpc.ldmd
>     -rwsr-xr-x   1 root     ustaff    515768 Mar 11 11:11
/local/ldm/bin/rpc.ldmd
>
> Check your LDM program for ownership and setuid.
>
> > If I try rpcinfo -t linus 300029 6 from linus, I get:
> > rpcinfo: RPC: Unable to receive; errno = Connection reset by peer
> > program 300029 version 6 is not available
>
> The above could mean that the rpcinfo(1) utility was able to connect
> to the LDM server on Linus (after getting the LDM port number from the
> portmapper) but was not able to receive a reply to the NULLPROC RPC
> message that it sent to the LDM server because the LDM server decided to
> close the connection rather than reply.  This is likely due to a missing
> ALLOW entry in the LDM configuration-file, etc/ldmd.conf, that enables
> the LDM to accept connections from the local system.  For example:
>
>     allow ANY ^(localhost|loopback|127\.0\.0\.1)$
>
> Check the LDM configuration-file on Linus for a similar entry.
>
> Execute the command
>
>     nslookup 127.0.0.1
>
> on Linus to ensure that the loopback hostname is either "localhost" or
> "loopback".
>
> > rcpinfo commands from an outside host to linus just hang or timeout.
>
> This likely due to a firewall blocking access to either the portmapper
> or port 46579.  Access to the portmapper is necessary in your case
> because the LDM server isn't listening on the well-known LDM port, 388.
>
> Try the command
>
>     rpcinfo -n 46579 -t linus 300029 6
>
> from a host other than Linus.  You might get the same behavior as when
> executing the rpcinfo(1) command on Linus.
>
> > I can ldmping from linus to cirque when cirque is connected as
> > ras9.ucar.edu, but I can't ldmping from cirque to linus.
>
> The inability to ldmping(1) Linus from Cirque is consistent with a
> firewall blocking access to the portmapper on Linus.
>
> > I can receive data from idd.unidata.ucar.edu on linus. Is
> > idd.unidata.ucar.edu outside NCAR's firewall?
>
> Yes.
>
> > So linus works as a downstream ldm, but does not work
> > as an upstream ldm.  Do I have to have port 46579 open on linus?
>
> That would only work one time.  The next time the LDM server on Linus
> was executed, it would, undoubtably, get a different port number.
>
> > I'm not sure why this port shows in the rcpinfo instead of port 388.
>
> See above.
>
> > I'm not really sure how the internals of ldm work when trying to get
through
> > the firewall.  I've had other people looking at this without much
> > success.  If you have any other info that might help me get this figured
> > out, that would be helpful.
>
> Is there any chance we could logon to Linus and Cirque as the LDM user?
> We're responsible, good at our jobs, and this would speed-up things
> considerably.
>
> > Thanks,
> > Janet
>
> Regards,
> Steve Emmerson
> LDM Developer
>-- End of excerpt from Steve Emmerson