A network map that draws itself, and only draws what it can prove
The collector reads what your switches and routers already know about their neighbours and builds the map for you. Where it has evidence it draws the link. Where it is making a best guess the line is dashed and labelled inferred, so you always know what to trust.
Topology maps are included on the free plan.
Built from what the network itself reports
LLDP and CDP
Neighbours reported by the devices themselves. Both ends are matched into a single link, with the port names on each side.
Switch forwarding tables
When a switch does not report LLDP or CDP, its MAC address table shows which port a device is behind. A link is only drawn when that device is the only one on the port, so a busy uplink never produces a false switch-to-switch link.
Three views
A physical map from the gateway down, a hierarchy of devices by role, and a logical map with a box for each subnet, joined by the routers between them.
Honest about gaps
A link that is a best guess is drawn dashed and labelled inferred, never presented as fact. A panel also tells you which switch needs LLDP or SNMP turned on to complete the map.
Ports and VLANs
Open a switch to see every port with its status, traffic and VLAN setting, including which are access ports and which are trunks.
Draw the rest by hand
For anything a map cannot see, use drag-and-drop diagrams and floor plans, and keep your documentation in the same place.
How each kind of link is shown
Every link carries a text label, and a best guess is dashed, so you never have to rely on colour to tell them apart.
| Evidence | How it is shown |
|---|---|
| LLDP or CDP report from the devices | A solid link labelled LLDP or CDP, with the port on each end |
| A single device seen on a switch port | A link labelled FDB (forwarding table) |
| Switches that each learned the other, with nothing else behind | A link labelled FDB between the two switches |
| Several devices on one port with no better evidence | A dashed "unmanaged switch" labelled inferred, joining them |
| Nothing has reported where a device plugs in | A dashed line labelled inferred, drawn to the gateway |
Questions
Do I need LLDP or CDP turned on?
It gives the best map, because the devices tell NetDraw exactly who their neighbours are. Without it NetDraw falls back to forwarding tables, and anything it still cannot prove is drawn dashed and labelled inferred.
Which devices does it read?
Any switch, router or firewall that answers SNMP v1, v2c or v3 and reports LLDP, CDP or a bridge forwarding table. Devices that do not answer SNMP are still listed, but they cannot report their neighbours.
Does the map update by itself?
Yes. The collector rereads the evidence on every discovery cycle and the map is rebuilt from the latest results, so a moved cable shows up without you redrawing anything.
Is it free?
Topology maps are included on the free plan, alongside monitoring of up to 5 devices. Seeing every discovered device needs a paid plan.
Can I edit the links by hand?
Not on the automatic map, which only shows what the network reports. For things it cannot see, draw your own diagram or floor plan alongside it.
More from NetDraw
Free SNMP monitoring
Monitor up to 5 devices for free, with no server to build.
SNMP monitoring for MSPs
Every client site in one place, with roles per site.
Remote device access without a VPN
Open a device's own web page through the collector.