threshold/website/content/docs/concepts/host-discovery/index.mdx

---
layout: docs
page_title: Host discovery
description: >-
  Learn how host discovery workflows let Boundary discover and onboard new resources. Understand how dynamic host catalogs enable automated host discovery.
---

# Host discovery

Traditionally, connecting to remote hosts and services requires knowledge of
the endpoint’s connection info (e.g. the IP address and port of the service).
This creates complexity when managing the onboarding of new resources at scale
or dealing with dynamic, ephemeral services whose connection info frequently changes.
Furthermore, the increased operational overhead of having to manually manage and update
new or old resources is an inefficient use of time.
Resources should be tagged appropriately so that, depending on their identity, users
automatically have the resources that they are allowed to connect to.

**Host discovery** focuses on automating the process of onboarding new or
changed infrastructure resources – and their connection info – to Boundary
as hosts.

## Automated host discovery in Boundary

Boundary supports target/host discovery in three primary workflows:

**[Manual configuration](/boundary/tutorials/oss-administration/oss-manage-targets)**:
Boundary administrators can manually configure static
hosts and targets via the administrator UI and CLI. Manual configuration of
targets with static hosts requires knowledge of the IP address or endpoint used
to connect to a host.

**[Host discovery via configuration as code with Terraform](/boundary/tutorials/oss-getting-started/oss-getting-started-config)**:
Boundary is fully programmatically instrumented and the discovery and configuration of new
infrastructure targets can be automated with
[Boundary’s Terraform provider](https://registry.terraform.io/providers/hashicorp/boundary/latest/docs).
This allows for dynamic configuration of a host and target without the need
for prior knowledge of the target’s connection info.

**[Runtime host discovery via dynamic host catalogs](/boundary/tutorials/host-management/aws-host-catalogs)**:
Boundary dynamic host catalogs automate the ingestion of resources from
infrastructure providers into Boundary. Boundary hosts are automatically
created, updated and added to host sets in order to reflect the connection
information maintained in these providers. This removes the need to know
host connection info or reapply infrastructure as code templates to
configure new or changed resources.

## Dynamic host catalogs
Dynamic host catalogs are an agentless workflow for Boundary to
securely query infrastructure providers at runtime to discover and configure
new services. Boundary administrators can define rules for which
external resources should be ingested into the catalog by
[creating a host sets](/boundary/docs/concepts/domain-model/host-sets)
with an attributes filter. These filters specify which discovered hosts
should be members of the host set.

Boundary currently supports dynamic host catalog for AWS, Azure, and GCP.
We will continue to grow this ecosystem to support additional providers.

## Next steps
To get started with dynamic host catalogs, refer to the following topics:

- [AWS dynamic host catalogs](/boundary/docs/concepts/host-discovery/aws)
- [Azure dynamic host catalogs](/boundary/docs/concepts/host-discovery/azure)
- [GCP dynamic host catalogs](/boundary/docs/concepts/host-discovery/gcp)