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The default user and password to login in on the WebUI is user: nmis and password: nm1888
After your login in that will be the primary screen.
NMIS Configuration
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1º Option: Click on the "Add Nodes button"
When you add a new node the required fields will be name, host name/IP Address, Group, and SNMP community if you are using SNMP for collect or WMI username and password if you are using WMI for collect.
Then scroll to the bottom and click on the "Add and Update Node" button.
2º Option: We can create a node from the GUI using the menu System > System Configuration > Nodes (Devices):
Click on the blue add button.
Follow the same instruction above to add nodes.
It is also possible to import nodes using the node administration tools - how to add bulk nodes.