Skip to main content

Synthetic Devices

A synthetic device stands in for connectivity Forward can't collect directly: the public internet, a leased L3 VPN, a carrier WAN circuit, an encrypted tunnel. You define it, and Forward models paths through it so traffic continues across the uncollected segment instead of dead-ending at the edge of your collected network.

Synthetic devices model user-defined connectivity. They are not a substitute for collection. If a physical device is reachable and you have credentials, collect it — a synthetic device is for the segment you genuinely can't reach.

Two stacked diagrams of the same six edge routers. In the top diagram the routers interconnect through a service-provider transport Forward can't collect, so modeled paths dead-end at each router's uplink. In the bottom diagram a single synthetic device stands in for that transport, so site-to-site paths continue across it.

In This Section​

PageWhat it covers
OverviewWhat synthetic devices model, how they fit the collected network, where they sit.
Choosing a DeviceWhich type to use for a given situation, and how the types differ.
Configuring ConnectionsUplink vs. gateway, VLAN, site, subnet auto-discovery, backdoor ports.
Automated Setup with NQEGenerating connections in bulk from an NQE query, with the schema and gotchas.
ReferencePer-type fields, constraints, locations, BGP collection, and API pointers.
Missing PeerThe placeholder Forward auto-creates for unmodeled uplink traffic.
Troubleshooting & FAQSymptom-keyed fixes for common synthetic-device problems.

Suggested Reading Order​

  • New to synthetic devices: read Overview, then Choosing a Device, then Configuring Connections.
  • Setting one up: Choosing a Device to pick the type, Configuring Connections for the field choices, and Automated Setup with NQE if you have many connections to add.
  • Looking up a field, constraint, or API path: go straight to Reference.

Where to Find Them​

To add or edit a synthetic device, open the Sources page and select the Synthetic nodes category.

Changes to a synthetic device — creating one, editing it, adding or removing a connection — take effect on the next processed snapshot, not the current one.