NetXMS Support Forum

I want to monitor laptops: they switch often from lan to wifi and vice versa. When they switch they get another ip (from dhcp) but also another interface and mac. netxms report that the node goes down but doesn't find the new ip an they stay down. I already set ResolveDNSToIPOnStatusPoll to 1. Now the new ip is found for the node (after the dnscache is cleared after some time on the server), but the interface itself stays with the old mac and ip and the node stays down. I have to do a manual poll for the full configuration to get the node up again, but the old interface is then deleted and replaced by the new interface. until the end users switches again...

How can I make netxms to recognize the node with both interfaces (one up, the other down) an automtically dectect te active one and report the node up if at least one interface is active?

thanks!

We will need to test this internally. It should work this way, if dns name gets properly updated.

There's also an alternative approach to use tunnel connections - in this case nodes are connecting to server and are identified by their unique identifier.

We did some testing on this.

If the node has NetXMS agent, everything works properly - domain name is resolved into IP, we connect to agent on this IP, agent replies.
In this case agent will report that the node has two interfaces, one will be UP, the other DOWN. In interface configuration you would need to set expected status to IGNORE, otherwise one of the interfaces will always produce an alarm on the node.

The other case is when node does not has NetXMS agent. In this case we use ICMP checks, which take IP address from interface. The thing is that in current version IP address on interface is not updated on status poll.

Do I understand correctly that you do not have NetXMS agent on these laptops?

Thank you for taking the time to test this.

You are correct that i didn't install an agent on the laptop. We have a lot of them, most of them are thin clients, and installing an agent is not so practical.
It seems that i can manually add the 2 interfaces with MAC and IP. When i switch form wifi to lan the corresponding interface goes up/down on a status poll. Of course it would be nice if you could select that at least one interface should be up before otherwise de node wil be marked as down and generate an alarm.
But i had to manually add the IP in the interface, i wonder what will happen when DHCP gives another IP? Will the IP in the interface be updated?

Yes, it could be possible to create two interfaces manually for these nodes. If an interface is created manually, it will not be deleted (there's a flag about that not visible in UI).

As far as I know there's currently no built-in logic for interface failover. With some NXSL scripting it should be possible to set up a script DCI that is checking interface status and produces an alarm when both interfaces are down (and there could be some additional logic to avoid the alarm when these laptops are officially shut down).

But if an IP address changes for an interface, there will be a problem anyway.
SNMP could help, but thin clients could also not support it.

In general there's currently a flaw in the logic, it should get improved. I've created an issue for this: https://track.radensolutions.com/issue/NX-1952