> For the complete documentation index, see [llms.txt](https://docs.threatdefence.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.threatdefence.com/appliances/overview.md). # Overview ThreatDefence provides two types of appliances to collect and forward data to the SecOps platform: the **Network Sensor** for network detection and response (NDR), and the **Syslog Forwarder** for log collection from your existing infrastructure. Both are available as virtual appliances, with the Network Sensor also offered as a physical hardware option for larger environments. *** ### Network Sensor (NDR) The ThreatDefence Network Sensor provides passive monitoring of network traffic for visibility, intrusion detection, and behavioural analytics. It is available as a physical appliance for enterprise and data-centre environments, or as a virtual appliance for smaller or cloud-only deployments. * [Overview](/appliances/network-sensor/overview.md) — Deployment architecture, SPAN/port mirroring setup, and connectivity requirements * [Physical Sensor](/appliances/network-sensor/physical-sensor.md) — Hardware specifications and installation * [Virtual Sensor](/appliances/network-sensor/virtual-sensor.md) — Virtual appliance setup and configuration *** ### Syslog Forwarder The ThreatDefence Syslog Forwarder (**TD-SYSLOG-VM**) is a lightweight Linux virtual appliance that collects logs from your environment and forwards them securely over an encrypted TLS channel to the ThreatDefence platform. It runs on any common hypervisor or cloud provider, including VMware, Hyper-V, and AWS. * [Overview](/appliances/syslog-forwarder/overview.md) — Architecture, VM resource requirements, and supported platforms * [Deployment](/appliances/syslog-forwarder/deployment.md) — Step-by-step deployment guide * [Onboarding Syslog Data](/appliances/syslog-forwarder/onboarding-syslog-data.md) — Configuring your devices to send logs --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.threatdefence.com/appliances/overview.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.