~= will replace $1 which is instance on entry with first capture group, but you don't have one, so returning empty string. Server consider empty string as instruction no use original instance. Also, your regular expression is wrong. Something like this should work (didn't actually test it):

// Each line has format
// index addr type macaddr name
if ($1 ~= "[0-9]+ 10\\.200\\.[0-9]+\\.[0-9]+/[0-9]+ [0-9]+ [0-9A-Fa-f]+ (.*)")
{
   return %(true, $1);
}
return false;

This script checks that IP address part starts with 10.200 and extracts interface name as new instance.

Best regards,
Victor

in instance Discovery ...

I configured parameter as Net.Interface.BytesOut({instance}) and in instance discovery I am using Agent List with List name Net.InterfaceList. I found some source code on this forum, so I modified it to:

if ($1 ~= "10.200.*.*")
{
   return %(true, $1);  // at this point $1 contains first matching group
}
return false;

But it is not working, I guess that if statement ($1 ~= "10.200.*.*") is incorrect. I would like to return one instance which start with 10.200 IP address. Any idea how to do that? Thank you

Edit: Well, it is returning whole instance (ifType, IP, MAC Name) ... How I can return only Name?

filter where exactly?

Best regards,
Victor

I was using template for these parameters and somehow one server refused to rename network interface to Ethernet (it showed as renamed but it wasn't). That's why it was reporting as unsupported ...)

Anyway, do you know how can I filter interface name by the first bytes of IP Address?

For an example, I have 10 network interfaces and one of them has IP 192.168.1.10 and I would like to return this one specific instance which begins by 192.168 ...

Thank you

it does not support Net.Interface.BytesOut(Ethernet). This is very strange.

does it support Net.Interface.BytesOut(Ethernet)?

Best regards,
Victor