Can a Dynamic DNS node be monitored?

If you do an nslookup from the command line, what is the IP being returned?  The new or the old?

Doing a nslookup by name from the Orion NPM server gives me the new IP address. 

I worked with a tech at the Solarwinds Support Team.  We first found out that the Dynamic DNS wasn't working properly.  I had a problem in my config that kept the router from transfering the new IP information to dyndns.org.  After that we found out that our Orion NPM server wasn't able to resolve the domain name with a nslookup.  That has been corrected and it resolves fine.  Now when the IP address changes at the ISP Orion NPM never picks it up.  It seems strange to me though that when I add the node only entering the domain name of the device it will resolve it to the correct IP.  If Orion can resolve the name when I add the node why can't it resolve it at a certain interval afterwards? 

Does anyone have any ideas?  

Hi Scaviness--

I'll forward this over to support to give them a heads up so they can chime in with any answers they might have.

M

Does anyone have any new ideas on this?  I still have the same problem.

I've made some investigation about this problem.

Orion NPM correctly handles IP address changes of monitored devices when valid forward DNS record with updated IP is present in DNS. Missing or mis-configured reverse DNS record seem not to be a problem for NPM. Monitored device IP address is automatically updated during next rediscovery. Standard polling does not do the IP address update, so monitored device is reported as "down" until next rediscovery occurs.

Maybe you can try to shorten the rediscovery interval for nodes with dynamic IP addresses to reduce the time when device is reported as "down". And of course don't forget to check the "dynamic IP address" check box when adding a node to Orion.

Monitoring this DDNS device still does not work.  I don't think shortening the rediscovery interval for the nodes would help since it never sees the change during any discovery.  The box is checked for "dynamic IP address". 

It seems like to me DDNS is not supported by Orion NPM.  It is strange though that when I add the node by name it resolves that name to the correct IP address of the router at that time.  Why can't NPM have a setting to make it resolve the name during the next rediscovery or polling?

I'm sorry, I've tested this on my developement machine and it worked. It is possible that my environment didn't match yours. If my DNS records were set-up correctly Orion worked. Dynamic IP address was updated correctly during rediscovery.

We are also having a problem with the DDNS issue (v9.5 SP4), and testing shows that the first poll correctly resolves the entered hostname (e.g. myhost.dyndns.org). But after that is complete, the Nodes.DNS field is populated with the reverse lookup (e.g. 123-45-67-89.pool.isp.net), while the Nodes.Caption field remains unchanged. Packet captures show that subsequent polls are querying the DNS field, not the Caption. Thus, even when the Dynamic IP is updated, NPM continues to poll the reverse lookup hostname, not the dynamic hostname.

An older post from Karlo Zatylny (SW) also refers to this mismatch, but unfortunately there aren't any specifics on why this occurs nor a specific way to change this DNS value (via SQL, then restart NPM?). Would this have to be done for each dynamic node, immediately after it was added to Orion? I'm also curious if Orion would replace this value anyways the next time it polls? It appears from this and several other posts that true Dynamic DNS is not supported, despite the "Dynamic IP" checkbox - is there a patch or hotfix in the works?

-Jordan