Planning for discovery

The following notes help you plan for the discovery.

Saving changes in the Network Discovery Configuration GUI

To save configuration changes that you have made during a session, remember to click the Save button before you log out, close the browser window, or close the Network Discovery Configuration tab. It is good practice to click Save as you move from tab to tab.

Operating system

Ensure that the host on which Network Manager is running is fully patched with the latest patches.

Discovery scope

Consider the following questions and points related to the discovery scope:

• Is the positioning of the Network Manager host within the network?
• Is the host positioned to interrogate all devices that you want to include in your discovery?
• Consider all necessary networks, subnetworks and determine the associated netmasks.
• Are there any parts of the network that you want to exclude?
• Gather all relevant SNMP community strings for the devices within the scope

Routing

Ensure that each of the networks and subnetworks to be discovered is reachable using the ICMP process. If necessary, add routes to Network Manager host machine using the route add command.

Access control lists

Network Manager uses several protocols that might need to pass through firewalls. These protocols are ICMP, SNMP, DNS, ARP, SSH, and TELNET. To ensure that Network Manager can access devices behind these firewalls, advise the relevant firewall administrators to prepare the firewalls.

Root cause analysis

To perform root cause analysis on devices within a topology, the discovery must identify all the devices on which you might want to perform root cause analysis. In addition, the Network Manager polling station must be known. If the polling station, usually the Network Manager server, is not within the scope of your network domain, then, to enable the RCA plug-in to perform isolated suppression, the IP address or DNS name of the ingress interface must be specified as the poller entity. This is the interface within the discovery scope from which network packets are transmitted to and from the polling station.