Best Practices for Mapping Large Networks
If you are mapping large networks, consider the following best practices for improving the discovery performance.
MSP Network Topology uses a multi-level discovery engine, which uses a combination of protocols and goes through three distinct phases to discover every node on a network and to produce a highly accurate map. As a result, the following factors can slow down the discovery:
- The size of the network being scanned
- The choice of node detection protocols used for the scan
- The number of hops specified for the scan
- Where the scan is being performed from
SolarWinds MSP Canada ULC recommends you consider the following to help you improve the performance of MSP Network Topology as it discovers devices on your network.
The tradeoff between the discovery speed and the discovery size.
Most users try to discover their entire network on the first scan. However, if you have a network with more than 1200 nodes, you are in for a long wait and at the end of it, the map might look very cluttered. The smaller the range you define to scan, the faster you will receive the results and the easier it will be to interpret them.
If you are discovering your network at common frequencies, such as once a week or once a month, you can discover many class C networks. If you need to run discoveries daily or if you need to complete the discovery fast, make your scans extremely small, such as 256 IPs or less.
Place the most commonly used credentials at the top of the list, be it SNMP, WMI or VMWare to enhance the discovery.
Do not use any unnecessary credentials. The more credentials there are, the longer discovery will take.
Zero Hop Discovery
When prompted to provide the number of hops to use during the scan, use zero hops unless you are not finding all of your expected devices. The more hops the scan goes through, the longer it takes and zero usually gets them all.
Scan from the same Management VLAN of your network to improve the speed of the discovery process. This reduces polling timeouts compared to scanning over VPN, dial-up or routing through another network.
If you manage a large network or you see your network growing in the coming months, run the discovery process during evening hours or on weekends and have your map ready for Monday morning. Make sure you have entered the proper credentials into the discovery wizard. Make sure to test your credentials before beginning the discovery process and leaving the building.