boundary/website/content/docs/getting-started/connect-to-target.mdx

---
layout: docs
page_title: Connect to Target
description: |-
  Connecting to your first target
---

## Connect to Your First Target

The default target is a `tcp` target with a default port of `22` (which
corresponds to the default SSH port using TCP). The host sets for this target
contain the default host, which has the address `127.0.0.1`. When we run
`boundary connect` against this target, the single available host will be
selected and we'll open a local authenticated proxy to the host on the target's
default port (`127.0.0.1:22`).

```
$ boundary connect -target-id ttcp_1234567890
```

In the output you'll see the address and port that your SSH client must be told
to use. In the next section you'll see the `ssh` connect helper in action to
make it easier to connect to the target with a client.

`boundary connect` has a number of options; one notable option is `-listen-port`
to choose the port on which the connect command will listen for an incoming
connection. This can be convenient for allowing Boundary to work with
applications that allow you to select the address to connect to but not the
port, but for many applications there are still some extra hurdles that can
exist, which is why we are building out helpers.

The dev-mode default target allows you to make as many connections as you want
within the authorized session. When you are finished making connections, simply
`Ctrl-C/Command-C` the `boundary connect` process to shut down the session.

### Using Connect Helpers

It can be annoying to keep accepting host SSH key prompts as the port changes,
much less having to keep copying and pasting the current port. To make this
easier, Boundary includes connect helpers that take care of this work for you.
These take the form of `boundary connect <subcommand>`. In the following
example, the helper will automatically execute `ssh` for you, filling in the
local address/port, and setting an expected host ID so that future connections
on different automatically-allocated ports don't complain about the host ID
changing (you'll still need to accept a host key the first time):

```
$ boundary connect ssh -target-id ttcp_1234567890
```

If you want to pass additional flags to the SSH client, you can do so by adding
them to the command line separated by a double-dash; anything after the double
dash will be passed to the executed client. For instance:

```
$ boundary connect ssh -target-id ttcp_1234567890 -- -l some-other-user
```

There is also a `-style` flag to allow the command to format arguments in a
different style expected by different SSH clients. At the moment, besides `ssh`
(the default), the `boundary connect ssh` command supports `-style putty` to
support passing connection information to PuTTY.

One advantage to styles is that Boundary will provide information to the client
in the format that makes sense. For example, if you want to specify a username
other than your currently logged-in user, you can do so via the `-username`
flag. This will ensure that regardless of whether you use the default `ssh`
style or the `putty` style, the username is properly passed to the executed
client -- you don't need to figure out the syntax yourself.

## Selecting Targets

When using `boundary connect` you must identify the target used for connecting.
Convention in this documentation is to use the target ID as that's a single
value and most explicit; however, other flags are supported:

- `target-name`: The name of the target
- `target-scope-id`: The ID of the scope in which the target lives
- `target-scope-name`: The name of the scope in which the target lives

Note however that these are not uniquely identifying as names can be re-used
across scopes. As a result, when not using the target ID, you must use the
target's name in conjunction with the scope name or scope ID so that Boundary
can correctly identify the desired target.

## Built-In vs. Exec

Boundary comes with built-in wrappers for popular layer 7 connection protocols,
such as:

- `ssh`: defaults to the local SSH client (`ssh`)
- `postgres`: defaults to the official Postgres CLI client (`psql`)
- `rdp`: defaults to the built-in Windows RDP client (`mstsc`)
- `http`: defaults to `curl`
- `kube`: defaults to `kubectl`

However, `boundary connect` can accommodate executing clients even when there is
no built-in support for a specific client using `-exec`. The `-exec` flag is a
very powerful tool, allowing you to wrap Boundary TCP sessions in your preferred
client. You can use this flag to create an authenticated proxy to almost
anything.

In all cases, whether using `-exec` or one of the listed helpers, you can pass
flags to the executed command by including them after a double-dash `--`:

```
$ boundary connect ssh -target-id ttcp_1234567890 -- -l myuser -i ~/.ssh/identity
```

You also have access to some templated values that are substituted into the
command arguments, and these values are additionally injected as environment
variables in the executed command:

- `{{boundary.ip}}` (`BOUNDARY_PROXIED_IP`): The IP address of the listening
  socket that `boundary connect` has opened.
- `{{boundary.port}}` (`BOUNDARY_PROXIED_PORT`): The port of the listening
  socket that `boundary connect` has opened.
- `{{boundary.addr}}` (`BOUNDARY_PROXIED_ADDR`): The host:port format of the
  address. This is essentially equivalent to `{{boundary.ip}}:{{boundary.port}}`.

For example, if you wanted to use Boundary to create an authenticated firewall
around 'curl', you could update the default TCP target from a default port
of `:22` to `:443`:

```
$ boundary targets update tcp -default-port 443 -id ttcp_1234567890

Target information:
  Created Time:               Fri, 25 Sep 2020 18:35:47 PDT
  Description:                Provides an initial target in Boundary
  ID:                         ttcp_1234567890
  Name:                       Generated target
  Session Connection Limit:   1
  Session Max Seconds:        28800
  Type:                       tcp
  Updated Time:               Fri, 25 Sep 2020 18:36:18 PDT
  Version:                    2

  Scope:
    ID:                       p_1234567890
    Name:                     Generated project scope
    Parent Scope ID:          o_1234567890
    Type:                     project

  Host Sets:
    Host Catalog ID:          hcst_1234567890
    ID:                       hsst_1234567890

  Attributes:
    Default Port:             443
```

In the output above the default port for the target has now changed to `:443`.

Now, `curl` can be used as the executed client for the TCP target session to do
an authenticated download of hashicorp.com:

```
$ boundary connect -exec curl -target-id ttcp_1234567890 \
         -- -vvsL --output /dev/null hashicorp.com

*   Trying 76.76.21.21...
* TCP_NODELAY set
* Connected to hashicorp.com (76.76.21.21) port 80 (#0)
> GET / HTTP/1.1
> Host: hashicorp.com
> User-Agent: curl/7.64.1
> Accept: */*
...<truncated output>...
```

Note that `-exec` is available for subcommands that wrap clients as well. As an
example, if `putty.exe` is available on a Windows host but the command is being
run from WSL, the following allows usage of the wrapper but while specifying the
correct available binary, as WSL must use `.exe` when invoking Windows binaries:

```
$ boundary connect ssh -style putty -exec putty.exe -target-id ttcp_1234567890
```

## Connect using Desktop Client

While using desktop client, choose target and connect to retrieve local proxy
details.

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  class="boundary-clickthrough-video boundary-clickthrough-desktop-video"
>
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    type="video/mp4"
    src="https://www.datocms-assets.com/2885/1613612836-boundary-desktop-clickthrough-connect-target-v1-0-0.mp4"
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## Next Steps

See our [basic administration workflows](https://learn.hashicorp.com/collections/boundary/basic-administration) for in depth discussion on managing scopes, targets,
identities, and sessions.