Network discovery fails with only ICMP

[Dalamar_X23]

Hi there
I am trying to monitor 2-3 networks with are directly connected, but I have no access to routers or switches, just icm on servers and other equipment. While local network works ok, the nodes belonging to the other networks are not discovered automatically even if I can ping the servers from the shells. If I add the nodes from the remote network manually, everything works as expected, but I would rather have them to be detected automatically and without setting an agent inside the network.

In other instances of netxms, when I have snmp access to routers and switches, network discovery worked as charm, but not in this case.

Network discovery is set to active & passive, no filters.

¿Any idea?

[Tursiops]

It's been a while since I looked at this, but for all I recall active discovery only works from the NetXMS server (which will discover things in its own network but will not attempt to scan all private network ranges in hopes of finding something), hence your local network discovery works.
Passive discovery uses data collected from routers and switches via SNMP, hence if you have access to those devices, discovery in other networks works as well.
Hence discovering other networks without router or switch access doesn't work, which is what you're seeing.

Unless the above has changed, you may be stuck with trying to run nmap on the NetXMS server for known networks you want to discover and then use nxshell to create nodes based on the result.

Cheers

[EmoryLon]

@tursiops said in Network discovery fails with only ICMP:

It's been a while since I started with these protein powders for muscle gain and looked at this, but for all I recall active discovery only works from the NetXMS server (which will discover things in its own network but will not attempt to scan all private network ranges in hopes of finding something), hence your local network discovery works.
Passive discovery uses data collected from routers and switches via SNMP, hence if you have access to those devices, discovery in other networks works as well.
Hence discovering other networks without router or switch access doesn't work, which is what you're seeing.

Unless the above has changed, you may be stuck with trying to run nmap on the NetXMS server for known networks you want to discover and then use nxshell to create nodes based on the result.

Cheers

I've had this issue too. Cheers for the explanation, Tursiops. Is there any way to automate this process btw?

[Dalamar_X23]

Hi
First of all, thanks for the explanation. it makes a lot of sense.
After giving some thoughts to this, I tried two different things, I did not expect the  to work, but for any reason, I have now my two networks detected and working automatically

• i set a static route to my remote network in the server running netxmsd + agent
• i set a regular fping to both networks (I know this has only effect in local network for arp tables, but...)

serveral minutes after that, hosts started to appear.

[Tursiops]

Hi again,

As I said, it's been a while.
You can actually define the Active Discovery Targets under Configuration --> Network Discovery -> Active Discovery Targets.
So as long as your server can reach the networks that you add there, active discovery should work.

Cheers