Transport Modes - Red Hat ENTERPRISE LINUX 5 - VIRTUALIZATION GUIDE Manual

Chapter 21. Remote management of virtualized guests

21.3. Transport modes

For remote management, libvirt supports the following transport modes:
Transport Layer Security (TLS)
Transport Layer Security TLS 1.0 (SSL 3.1) authenticated and encrypted TCP/IP socket, usually
listening on a public port number. To use this you will need to generate client and server certificates.
The standard port is 16514.
UNIX sockets
Unix domain sockets are only accessible on the local machine. Sockets are not encrypted, and
use UNIX permissions or SELinux for authentication. The standard socket names are /var/
run/libvirt/libvirt-sock and /var/run/libvirt/libvirt-sock-ro (for read-only
connections).
SSH
Transported over a Secure Shell protocol (SSH) connection. Requires Netcat (the nc package)
installed. The libvirt daemon (libvirtd) must be running on the remote machine. Port 22 must be
open for SSH access. You should use some sort of ssh key management (for example, the ssh-
agent utility) or you will be prompted for a password.
ext
The ext parameter is used for any external program which can make a connection to the remote
machine by means outside the scope of libvirt. This parameter is unsupported.
tcp
Unencrypted TCP/IP socket. Not recommended for production use, this is normally disabled, but an
administrator can enable it for testing or use over a trusted network. The default port is 16509.
The default transport, if no other is specified, is tls.
Remote URIs
A Uniform Resource Identifier (URI) is used by virsh and libvirt to connect to a remote host.
URIs can also be used with the --connect parameter for the virsh command to execute single
commands or migrations on remote hosts.
libvirt URIs take the general form (content in square brackets, "[]", represents optional functions):
driver[+transport]://[username@][hostname][:port]/[path][?extraparameters]
The transport method or the hostname must be provided to target an external location.
Examples of remote management parameters
• Connect to a remote Xen hypervisor on the host named towada, using SSH transport and the SSH
username ccurran.
xen+ssh://ccurran@towada/
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