4354: Connection to Acronis Online Backup Service Fails with "The certification server is unavailable"

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Last update: Fri, 2014-10-03 10:09

Unblock the necessary hostname and the 55556 port

This article applies to:

  • Acronis True Image

Cloud storage is an add-on to Acronis True Image and can not be used without the product.


  1. In Acronis True Image, you try to log into your Acronis Online Backup account or back up to Acronis Online Backup server;
  2. The operation fails with the following error message:

    The certification server is unavailable


Acronis True Image Home cannot access the following hostname and port:

  • Hostname:

    US: cloud-rs-us1.acronis.com OR cloud-rs-us2.acronis.com

    EMEA: cloud-rs-eu1.acronis.com

  • Port: 55556

A firewall or some other security software on your machine is blocking the access.


Set up your firewall or other security software to allow access to the mentioned hostname and port. See also Acronis Online Backup Access Ports and Hostnames.

More information

If the required port and hostname are accessible, but the issue is still not resolved, please get the below information:

    1. Create C:\Acronis\ folder and get the output of the below commands (from Start -> Run -> cmd):
ping -n 50 cloud-rs-us1.acronis.com > C:\Acronis\ping_US1_RS.log

tracert cloud-rs-us1.acronis.com > C:\Acronis\tracert_US1_RS.log

ping -n 50 cloud-rs-us2.acronis.com > C:\Acronis\ping_US2_RS.log


tracert cloud-rs-us2.acronis.com > C:\Acronis\tracert_US2_RS.log

ping -n 50 cloud-rs-eu1.acronis.com > C:\Acronis\ping_EU1_RS.log

tracert cloud-rs-eu1.acronis.com > C:\Acronis\tracert_EU1_RS.log

  1. Close the Acronis product, and start capturing network traffic (see Collecting PCAP Logs) - then start Acronis Online Backup client and reproduce the issue by trying to log into your account;
  2. Collect Acronis System Report. See Acronis True Image Home 2010: Generating System Report or Acronis True Image Home 2011: Generating System Report.
  3. Contact Acronis Customer Service with the collected information:
    • ping.log
    • tracert.log
    • PCAP logs
    • Acronis System Report

See also: