Everything You Need To Know About Multiple Active RAS Publishing Agents
First of all, what is a RAS Publishing Agent? A RAS Publishing Agent (PA) provides load balancing of published applications and desktops. The RAS Publishing Agent is automatically installed upon the installation of Parallels Remote Application Server.
To safeguard users from any interruption, multiple PAs can be configured for the unlikely event that one of the PAs experiences any downtime. With Parallels RAS v15.5, multiple PAs can also be active on the same site; this will ensure that the load is distributed equally between the multiple active PAs.
This blog post shows you how to add and manage RAS Publishing Agents.
Adding a RAS Publishing Agent
Using Parallels RAS with multiple PAs, administrators can now ensure users do not experience any downtime, even in the event that the primary RAS PA is unavailable. As mentioned above, another advantage of having multiple PAs in the same site is that the load is distributed between the multiple active PAs.
Follow the steps below to add a RAS Publishing Agent:
- In the RAS console, navigate to Farm > Publishing Agents.
- In the Tasks drop-down menu, click Add to launch the Add RAS Publishing Agent Wizard.
- Specify the FDQN or IP address of the server that will host the new Publishing Agent.
- Select the Install a gateway with a publishing agent option if you also want to install a RAS Secure Client Gateway on the specified server.
- Select the Add Firewall Rules option to automatically configure the firewall on the server.
- Click Next.
- Click on the Install button to install the RAS Publishing Agent on the server. The Installing RAS Redundancy Service dialog opens.
- Once the installation has been completed, click Done.
- Click OK to add the server to the farm.
Congratulations, you have successfully added another Publishing Agent to the site.
Managing RAS Publishing Agents
Enabling or Disabling a Backup Publishing Agent

To enable or disable a backup Publishing Agent on a site, select it in the Publishing Agents list and then select or clear the check-box at the beginning of the row.
Changing Backup Publishing Agent Priority
Each RAS Publishing Agent in the list is given a priority. By default, the local RAS Publishing Agent is given the Master priority.
To change the priority of other Publishing Agents in the farm, select a Publishing Agent and click on Move Up or Move Down in the Tasks drop-down menu. The higher it is in the list, the higher priority it has.
Promoting a Publishing Agent to Master Publishing Agent
In the unlikely event that the primary Publishing Agent cannot be recovered, you can easily promote another Publishing Agent to Master Publishing Agent.
Follow the steps below to promote a Publishing Agent to Master Publishing Agent:
- Open the Parallels Remote Application Server Console on the server that you would like to promote.
- Select the Farm category and navigate to the Publishing Agents
- Select the RAS Publishing Agent and then click Promote Backup to Master in the Tasks drop-down menu.
- Click OK once the process is finished.
Deleting a Publishing Agent

To delete a Publishing Agent, select it in the list and then click Delete in the Tasks drop-down menu.
Firewall Requirements
The following ports are the communication ports for Parallels Remote Application Server that need to be enabled for access from both LAN and WAN.
- TCP 20002 – Publishing Agent Service Port – Communications with SecureClientGateway and UI Console
- TCP 20003 – Terminal Server Agent Port – Communications with Terminal Server agents
- TCP 20001 – Publishing Agent Service Port – Communication with other Publishing Agents
- TCP 20030 – Communication between multiple Publishing Agents
- Outbound TCP 443- Communication with Parallels Licensing Server:
- parallels.com
- parallels.com