I agree but will add: we see problems with ldmping even when there is no
firewall and our servers are actively connected, so YMMV.
My fallback is to netcat or telnet to the LDM port (388) to test. With
ldmping, it rarely works as described for me. Of the 15 or so servers we
connect to, I can only ldmping one of them, and of those 15 I run 4 of them
and fully control the network plane which is wide open, so...I would try
the netcat or telnet trick...or, if possible, ping or traceroute to the
IP/host from LDM user or with sudo powers as well. That can rule in or out
network/firewall issues...or it can also tell you (like I often
experience): "the connection works fine but ldmping is confused for some
other reason".
On Tue, Jan 19, 2021 at 9:26 AM Herzmann, Daryl E [AGRON] <
akrherz@xxxxxxxxxxx> wrote:
> Hi Robert,
>
> This certainly looks like a firewall/routing issue. Some things I would
> suggest checking.
>
> 1) Is there a routable network path between the LDM client and server and
> back to the client? Perhaps these devices are behind NATs which have their
> own firewalls? Are you able to connect from the client to the server on
> other ports, like SSH, HTTP, etc?
>
> 2) On the server, double check your firewall settings. If you can,
> temporally drop the server firewall and see if the LDM client can ping.
> Ensure that you don't have both iptables and firewalld running at the same
> time.
>
> 3) Can any other LDM client connect to this server?
>
> 4) On the client, ensure the server's FQDN doesn't exist in /etc/hosts
> with a different IP as you mentioned DNS already has it.
>
> daryl
>
> --
> /**
> * daryl herzmann
> * Systems Analyst III -- Iowa Environmental Mesonet
> * https://mesonet.agron.iastate.edu
> */
>
> ________________________________________
> From: ldm-users <ldm-users-bounces@xxxxxxxxxxxxxxxx> on behalf of
> Mullenax, Robert R. (WFF-820.0)[ORBITAL SCIENCES CORPORATION] via
> ldm-users <ldm-users@xxxxxxxxxxxxxxxx>
> Sent: Tuesday, January 19, 2021 11:14 AM
> To: ldm-users
> Subject: [ldm-users] Strange LDM connectivity issue
>
> Good morning,
>
> I rarely have LDM connectivity issues, but am having a weird one this
> morning. I have two systems, at our facilities in different states that I
> manage. Our NOAAport ingest machine is down at one location, so I want to
> feed from the LDM server at the other location that is being fed by another
> dish/NOAAport ingest machine. I have proper allows/request on both ends,
> DNS resolves correctly, SELinux (CENTOS 7) is disabled on both machines,
> and port 388 is allowed through firewall. Each machine is getting a
> non-NOAAPort data feed from another out-of-state LDM just fine.
>
> Ldmping results in:
>
> 20210119T171056.791467Z ldmping[11619] ERROR ldmping.c:75:print_hstat()
> SVC_UNAVAIL 10.097094 0 XXXXXXXXXXXX.com
> h_clnt_create(XXXXXXXXXXXXX.com): Timed out while creating connection
>
> Yet the server on the other end is running and all is nominal.
>
> Any ideas on what to check?
>
> Thanks,
> Robert Mullenax
>
> Robert Mullenax
> Staff Meteorologist
> CSBF/Northrop Grumman
> Palestine, Texas
> 903-729-0271
>
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