Hello Tom and all....
We ran into a problem with our LDM system: Hurricane.srcc.lsu.edu. When
opeating off site, Hurricane is not receiving LDM data. The offsite
location is the state Office of Emergency Preparedness (OEP) and this is
behind a firewall. This system operated, on location, until the LDM was
upgraded to the version 6.x. Hurricane operates correctly when running
locally at LSU which is the real non-firewalled open networking.
At OEP the system is connected to the internet via a NAT'ed (Network
Address Translation) firewalled network. As I indicated above the
problem has not occurred in earlier versions 5.2x but problems are
showing up in version 6.x.
The systems serving the LDM data is Datoo.srcc.lsu.edu and
Seistan.srcc.lsu.edu. I found the following errors in the logs:
Jul 19 16:45:12 seistan rpc.ldmd[24797]: gethostbyaddr: failed for
204.196.102.99
Jul 19 16:46:12 seistan rpc.ldmd[24797]: gethostbyaddr: failed for
204.196.102.99
Jul 19 16:47:21 seistan rpc.ldmd[24797]: gethostbyaddr: failed for
204.196.102.99
Jul 19 16:49:42 seistan rpc.ldmd[24797]: gethostbyaddr: failed for
204.196.102.99
Jul 19 16:50:04 seistan rpc.ldmd[24797]: gethostbyaddr: failed for
204.196.102.99
Jul 19 16:50:38 seistan rpc.ldmd[24797]: gethostbyaddr: failed for
204.196.102.99
The 204.196.102.99 address is the Nat'd address located on the 'real'
side of the internet. Seistan and Datoo are not able to reverse the
connection to the remote. Hurricane is able to connect to Seistan and
Datoo. Applications such as ssh, sftp and ldmping are able to connect to
Seistan and/or Datoo. LDM, however, will not complete a connection. The
servers, Seistan and Datoo detect connection requests, but when the
gethostbyaddr command fails in the reverse direction, the LDM stream is
not started. The servers "error out" the connection and produce the
errors above.
I am assuming there is a reason to do a gethostbyname in LDM version
6.X. I am also assuming the gethostbyaddr function was not part of the
earlier LDM 5.x versions as this problem was not apparent. No changes
have occoured in networking between OEP and our office at LSU since we
used it last year.
Can LDM be reconfigured to skip the gethostbyaddr function?. Or do I
need to set up another LDM server with old code?
Regards,
Bob
--
----------------------------------------------------------------
Robert Leche
System Administrator
Louisiana State University - Southern Regional Climate Center
E328 Howe-Russell Building
Baton Rouge, La. 70803
rleche@xxxxxxxxxxxx
225 578 5023
----------------------------------------------------------------
