## TCP Port and Address

Cockpit's `cockpit-ws` component is configured by default to accept connections on port `9090`. This is the port that is documented for a "Web-based System Manager" to listen on. It is also relatively memorable.

However there are many reasons you may wish to change the default port. For example other software may use port `9090` or you may wish to setup Cockpit to listen on `443` instead. It is also possible to have Cockpit only listen on one specific IP address.

Note that it is only required to have Cockpit listening on a TCP port on the server that you access with your web browser. If you add multiple servers to the Cockpit dashboard, Cockpit will connect to those servers via `ssh`.

The systems that Cockpit runs on are typically locked down with firewalls, SELinux, so changing the default port is not as easy as editing a configuration file.

## Cockpit systemd Socket

On servers with `systemd` Cockpit starts on demand via socket activation. To change its port and/or address you should place the following content in the `/etc/systemd/system/cockpit.socket.d/listen.conf` file. Create the file and directories in that path which not already exist. The `ListenStream` option specifies the desired address and TCP port.

    [Socket]
    ListenStream=
    ListenStream=443

    [Socket]
    ListenStream=
    ListenStream=192.168.1.1:443
    FreeBind=yes

NOTE: The first empty line is intentional. `systemd` allows multiple `Listen` directives to be declared in a single socket unit. To change the activation port instead of adding a second port, use a full override unit instead of a snippet.

The `FreeBind` option is highly recommended when defining specific IP addresses. See the `systemd.socket` manpage for details.

Cockpit can actually listen on multiple ports, also:

    [Socket]
    ListenStream=
    ListenStream=443
    ListenStream=7777

As above, it's recommended to start with an override unit, otherwise it's possible one of your multiple listen addresses might conflict.

In order for the changes to take effect, run the following commands:

    $ sudo systemctl daemon-reload
    $ sudo systemctl restart cockpit.socket

## SELinux Port

If SELinux is protecting your server, then you will need to tell it to allow Cockpit to listen on the new port. Run the following command to do so. The last argument specifies the desired TCP port.

    $ sudo semanage port -a -t websm_port_t -p tcp 9999

If the port is already defined by some other part of the SELinux policy, then you will need to use the `-m` argument to modify the definition. That's the case with the `443` SSL port, which is typically defined as an `http_port_t` port.

    $ sudo semanage port -m -t websm_port_t -p tcp 443

The changes should take effect immediately.

## Firewalld Port

If Firewalld is configured as your firewall, then you will need to tell it to allow Cockpit to receive connections on the new port. Run the following commands to do so. The last options specify the desired TCP port.

    $ sudo firewall-cmd [--zone=ZONE] --add-port=443/tcp
    $ sudo firewall-cmd --permanent [--zone=ZONE] --add-port=443/tcp