# 7.3. Listing Hosts on the Command Line

Many PRRTE commands accept the `--host` CLI parameter. `--host` accepts a comma-delimited list of tokens of the form:

    host[:slots]

The `host` token can be either:

- A name that resolves to an IP address, or

- An IP address

Note

The names and/or IP addresses of hosts are only used for identifying the target host on which to launch. They are not used for determining which network interfaces are used by applications (e.g., MPI or other network-based applications).

For network-based applications, consult their documentation for how to specify which network interfaces are used.

The optional integer `:slots` parameter tells PRRTE the maximum number of slots to use on that host (see this section on definition of the term `slot` for a description of what a “slot” is).

For example:

    prterun --host node1:10,node2,node3:5 ...