---
name: "systemd-ssh-proxy"
section: "1"
platform: "linux"
package: "systemd"
version: "262.1-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/systemd-ssh-proxy"
---

# systemd-ssh-proxy(1)

SSH client plugin for connecting to AF\_VSOCK and AF\_UNIX sockets

## NAME

systemd-ssh-proxy - SSH client plugin for connecting to **AF\_VSOCK** and **AF\_UNIX** sockets

## SYNOPSIS

```
Host unix/* unix%* vsock/* vsock%* vsock-mux/* vsock-mux%*
    ProxyCommand /usr/lib/systemd/systemd-ssh-proxy %h %p
    ProxyUseFdpass yes
```

**/usr/lib/systemd/systemd-ssh-proxy** \[ADDRESS\] \[PORT\]

## DESCRIPTION

**systemd-ssh-proxy** is a small "proxy" plugin for the [**ssh**(1)](/ssh/1.md) tool that allows connecting to **AF\_UNIX** and **AF\_VSOCK** sockets. It implements the interface defined by ssh's *ProxyCommand* configuration option. It's supposed to be used with an [**ssh\_config**(5)](/ssh_config/5.md) configuration fragment like the following:

```
Host unix/* unix%* vsock/* vsock%* vsock-mux/* vsock-mux%*
    ProxyCommand /usr/lib/systemd/systemd-ssh-proxy %h %p
    ProxyUseFdpass yes
    CheckHostIP no
Host .host
    ProxyCommand /usr/lib/systemd/systemd-ssh-proxy unix/run/ssh-unix-local/socket %p
    ProxyUseFdpass yes
    CheckHostIP no
```

A configuration fragment along these lines is by default installed into /etc/ssh/ssh\_config.d/20-systemd-ssh-proxy.conf.

With this in place, SSH connections to host string "unix/" followed by an absolute **AF\_UNIX** file system path to a socket will be directed to the specified socket, which must be of type **SOCK\_STREAM**. Similar, SSH connections to "vsock/" followed by an **AF\_VSOCK** CID will result in an SSH connection made to that CID. "vsock-mux/" followed by an absolute **AF\_UNIX** file system path to a socket is similar but for cloud-hypervisor/firecracker which do not allow direct **AF\_VSOCK** communication between the host and guests, and provide their own multiplexer over **AF\_UNIX** sockets. See **cloud-hypervisor VSOCK support**\[1\] and **Using the Firecracker Virtio-vsock Device**\[2\]. Note that "%" can be used as a separator instead of "/" to be compatible with tools like "scp" and "rsync".

Moreover, connecting to ".host" will connect to the local host via SSH, without involving networking.

This tool is supposed to be used together with [**systemd-ssh-generator**(8)](/systemd-ssh-generator/8.md) which when run inside a VM or container will bind SSH to suitable addresses. **systemd-ssh-generator** is supposed to run in the container or VM guest, and **systemd-ssh-proxy** is run on the host, in order to connect to the container or VM guest.

## EXIT STATUS

On success, 0 is returned, a non-zero failure code otherwise.

## EXAMPLES

**Example 1. Talk to a local VM with CID 4711**

```
ssh vsock/4711
```

**Example 2. Talk to a VM guest hosted with cloud-hypervisor/firecracker**

```
ssh vsock-mux/run/vm-1234.sock
```

**Example 3. Talk to the local host via ssh**

```
ssh .host
```

or equivalent:

```
ssh unix/run/ssh-unix-local/socket
```

**Example 4. Copy local 'foo' file to a local VM with CID 1348**

```
scp foo vsock%1348:
```

## SEE ALSO

[**systemd**(1)](/systemd/1.md), [**systemd-ssh-generator**(8)](/systemd-ssh-generator/8.md), [**vsock**(7)](/vsock/7.md), [**unix**(7)](/unix/7.md), [**ssh**(1)](/ssh/1.md), [**sshd**(8)](/sshd/8.md)

## NOTES

- 1\.

  cloud-hypervisor VSOCK support

  https://github.com/cloud-hypervisor/cloud-hypervisor/blob/main/docs/vsock.md

- 2\.

  Using the Firecracker Virtio-vsock Device

  https://github.com/firecracker-microvm/firecracker/blob/main/docs/vsock.md