Cloud Direct knowledge base

Ports used by Plan B technologies

The following information was sent from Plan B on the 12 Dec 2015 in response to a request for information from Cloud Direct.

Further information concerning Plan B products may be obtained by visiting their website at, by email at, or by phone on 08448 707 999.


Plan B Data Flows

In order for a Plan B Disaster Recovery service to work properly, the following connections must be possible:

Outbound from the Appliance to Plan B Systems

The Appliance will initiate outbound connections to the following:

  • TCP Ports 443 and 444 to:
    • - (Used to replicate data)
    • - (Used to replicate data)
    • (fallback IP address)
  • UDP Port 123 (NTP) for time synchronisation. Attached to ''. This is not vital but, without it, the time on the Appliance will slowly drift.
  • TCP Port 80 to Plan B Software Package Repositories. These are currently:
    • (
    • (

Connections from Plan B Appliances to Protected Hosts

  • TCP Port 12346 (this is the port that the Plan B Backup Agent listens on).
  • Multicast DNS (also known as 'Zeroconf'). This is used for agent discovery - it's not fatal if this isn't possible.