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Re: 20060113: Sending data through LDM to ground from aircraft with changing ip address (cont.)

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  • Subject: Re: 20060113: Sending data through LDM to ground from aircraft with changing ip address (cont.)
  • Date: Tue, 14 Feb 2006 17:16:14 -0700
Janet,

>Date: Tue, 14 Feb 2006 15:55:32 -0700
>From: Janet Scannell <address@hidden>
>Organization: UCAR/NCAR/EOL/ATD
>To: Steve Emmerson <address@hidden>
>Subject: Re: 20060113: Sending data through LDM to ground from aircraft with 
>changing ip address (cont.)

The above message contained the following:

> I tried the beta version of the ldm code that you made to fix this 
> problem.  What I found is that the ldm no longer reports error messages 
> in the log when the ip address changes and it can no longer reach the 
> old host, but the data from the new ip address on the plane to the 
> ground never gets to the downstream ldm.  It looks like part of the ldm 
> code is determining that the host name still exists, but there is still 
> some part that needs updating for the data to actually reach the ldm on 
> the ground.

I'm sorry to hear this.

At this point, the downstream LDM on the ground is doing all that it can
to obtain the correct IP address for the given hostname on the plane.
The lack of error messages indicates that the downstream LDM on the
ground is timing-out in its attempts to contact the upstream LDM on the
plane.  You should be able to see this by starting the LDM on the ground
in verbose mode via the "-v" option to ldmadmin(1) -- alternatively, you
can send a running downstream LDM process a USR2 signal to put it into
verbose mode.

I wish I could tell you something encouraging, but the network (not the
LDM) just isn't playing nice.

Tom, you got any ideas?

Regards,
Steve Emmerson