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Setting Up Update Agents and Local Update Servers

This Article Applies to:

  • Avast Business Hub


You can set up devices to act as Update Agents for other devices. Update Agents store identical copies of update files that reside on Avast's update servers. Other devices that you manage through the Console can download update files from Update Agents instead of contacting the Avast Update Servers.

Once you select a device to be an Update Agent, that device receives program updates and virus definitions over the web. You can then define which devices and groups use the device to update by selecting that mirror or Local Update Server in any policy. If you set up multiple Update Agents, your devices can update from another even if one is unavailable.

Only Windows devices can become Update Agents.

Scanning Agents

In addition to Update Agents to store and distribute program updates and virus definitions, you will need a Scanning Agent for Remote Deployment. For more information, see Network Discovery and Remote Deployment.

You will have to add a device before you can set it up as an Update Agent. See Adding Devices to Business HubAdding Devices to On-Premise Consolefor more details.

Devices and the Management Console still communicate directly for licensing, usage date, and threat notifications.

Agent Requirements

The device you use as an Update Agent must:

  • be online at all times
  • have a static IP address
  • be able to communicate with other devices on TCP port 4158 to share update files

We highly recommend you choose a server device for your Update Agent.

Setting Up Update Agents

  1. Navigate to the Devices tab
  2. Click the name of the device you would like to make into an Update Agent
  3. Beside the Update Agent option, click the slider to On
  4. Click Promote to confirm

It may take some time for the Update Agent services to activate on the device.

Local Update Servers

Devices that are acting as Update Agent during remote deployment can also be used as Local Update Servers for Program and Virus Definition updates. A local update server will download updates from Avast servers, and other devices on the network can then download updates from that device. In general, devices will automatically be set to use Update Agents as Local Update Servers, unless they are specifically set to use Avast servers only.

If more than one Update Agent/Local Update Server is available, devices will use a network ping to choose the closest Local Update Server for downloading the updates.


If you are having trouble with your Update Agent, please check the following:

  • The Update device is enabled correctly
    1. Navigate to C:\ProgramData\Avast Software\Business Agent\log
    2. Open the agent_log file
    3. Search for the lines: "is_master_agent_available_in_lan = X” and “is_this_computer_master = X"
      • On the Update agent, this line should be "is_this_computer_master = 1"
      • On other devices in your network, this line should be "is_master_agent_available_in_lan = 1"
  • The Update Agent DNS name can be resolved properly by devices
  • The Update Agent has access to Avast servers (see Firewall Requirements)
  • TCP port 4158 is not blocked between clients and the Update Agent

If you have verified these settings are all correct and you continue to experience issues with your Update Agent, please contact Business Technical Support.