My Window Is Full of Icons

When first discovery is finished, the Internet submap may be filled with a nest of wagon wheels. This is to be expected in corporate networks containing hundreds of routers and thousands of subnets. This large IP-centric display accurately portrays the network’s connectivity and is very useful for troubleshooting network problems once you get past first impressions. Still, there is a compelling reason to partition this large map into a few dozen containers. Ease of use is one reason, and response time is a second. The partitions usually represent management domains or geographic regions.

Even inside a subnet icon there may be hundreds of switches, bridges, routers, and segment icons. The panning tool is your friend here, since the task of partitioning each subnet is too labor-intense to be worth the effort.

In a subnet with many switches and hundreds of switch ports, the number of segment icons can be daunting. It’s possible to avoid displaying much of the layer 2 clutter using NNM 6.1’s -k segRedux=TRUE parameter in netmon.lrf. It eliminates segments with only two devices and connects them directly. If layer 2 layout isn’t of interest, you can use the -k bridgeMIB=FALSE option in netmon.lrf and no additional segments will be created for switch and bridge ports.

Note that segRedux is “on” by default for a clean install of NNM 6.1. It is “off” by default for upgrade situations.