ZMQ\_VMCI(7) 0MQ Manual ZMQ\_VMCI(7)

# [NAME](#NAME)

zmq\_vmci - 0MQ transport over virtual machine communicatios interface (VMCI) sockets

# [SYNOPSIS](#SYNOPSIS)

The VMCI transport passes messages between VMware virtual machines running on the same host, between virtual machine and the host and within virtual machines (inter-process transport like ipc).

**Note**

Communication between a virtual machine and the host is not supported on Mac OS X 10.9 and above.

# [ADDRESSING](#ADDRESSING)

A 0MQ endpoint is a string consisting of a *transport*:// followed by an *address*. The *transport* specifies the underlying protocol to use. The *address* specifies the transport-specific address to connect to.

For the VMCI transport, the transport is vmci, and the meaning of the *address* part is defined below.

## [Binding a socket](#Binding_a_socket)

When binding a *socket* to a local address using *zmq\_bind()* with the *vmci* transport, the *endpoint* shall be interpreted as an *interface* followed by a colon and the TCP port number to use.

An *interface* may be specified by either of the following:

• The wild-card \*, meaning all available interfaces.

• An integer returned by VMCISock\_GetLocalCID or @ (ZeroMQ will call VMCISock\_GetLocalCID internally).

The port may be specified by:

• A numeric value, usually above 1024 on POSIX systems.

• The wild-card \*, meaning a system-assigned ephemeral port.

## [Unbinding wild-card address from a socket](#Unbinding_wild)

When wild-card * *endpoint* was used in *zmq\_bind()*, the caller should use real *endpoint* obtained from the ZMQ\_LAST\_ENDPOINT socket option to unbind this *endpoint* from a socket using *zmq\_unbind()*.

## [Connecting a socket](#Connecting_a_socket)

When connecting a socket to a peer address using *zmq\_connect()* with the *vmci* transport, the *endpoint* shall be interpreted as a *peer address* followed by a colon and the port number to use.

A *peer address* must be a CID of the peer.

# [EXAMPLES](#EXAMPLES)

**Assigning a local address to a socket**.

```
//  VMCI port 5555 on all available interfaces
rc = zmq_bind(socket, "vmci://*:5555");
assert (rc == 0);
//  VMCI port 5555 on the local loop-back interface on all platforms
cid = VMCISock_GetLocalCID();
sprintf(endpoint, "vmci://%d:5555", cid);
rc = zmq_bind(socket, endpoint);
assert (rc == 0);
```

**Connecting a socket**.

```
//  Connecting using a CID
sprintf(endpoint, "vmci://%d:5555", cid);
rc = zmq_connect(socket, endpoint);
assert (rc == 0);
```

# [SEE ALSO](#SEE_ALSO)

[**zmq\_bind**(3)](/man/os/zeromq/zmq_bind.3) [**zmq\_connect**(3)](/man/os/zeromq/zmq_connect.3) [**zmq\_inproc**(7)](/man/os/zeromq/zmq_inproc.7) [**zmq\_tcp**(7)](/man/os/zeromq/zmq_tcp.7) [**zmq\_pgm**(7)](/man/os/zeromq/zmq_pgm.7) [**zmq\_vmci**(7)](/man/os/zeromq/zmq_vmci.7) [**zmq\_getsockopt**(3)](/man/os/zeromq/zmq_getsockopt.3) [**zmq**(7)](/man/os/zeromq/zmq.7)

# [AUTHORS](#AUTHORS)

This page was written by the 0MQ community. To make a change please read the 0MQ Contribution Policy at **http://www.zeromq.org/docs:contributing**.

10/26/2026 0MQ 4.3.5

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Document: zmq_vmci(7) from zeromq 4.3.5-r15 (Chainguard OS)
Source: https://github.com/zeromq/libzmq