Articles on: SECURITY

Network Requirements for Host Managed by CMC / CPC

This article is about network requirements during the post-installation operational phase of Cirrus Migrate Cloud software. For network requirements during installation, please see Network Requirements for Cirrus Migrate Cloud Installation

Network Requirements for a Host Managed by Cirrus Migrate Cloud / Cirrus Protect Cloud

Inbound Network Requirements

There is no need to allow any inbound connections to the user's hosts with Cirrus Migrate Cloud or Cirrus Protect Cloud installed except for remote migration to/from another host which requires setting up a H2H connection. In that case, only one of the two hosts needs to have an inbound rule regardless of the direction of data transmission.

Please refer to the help article How to establish host-to-host (H2H) network connections for remote migration for details on setting up direct connections between a source host and destination.

Outbound Network Requirements

For a host to be managed by the Cirrus Migrate Cloud or Cirrus Protect Cloud Portal Project, the deployed CMC software must initiate 1-way outbound TCP connections to Cirrus Data Cloud. For security reasons, no inbound connections are made, thereby avoiding the need to open up any inbound port(s).

The following outbound security rule for the host should be configured:
Allow TCP protocol, Port 443, to which is currently at
Ensure is resolvable by DNS (or via OS host file)

Note: if no-http2 mode is used (see below), the cloud portal endpoint would be at instead of

Proxy Servers

In addition, http/https proxy servers are fully supported to improve security. Please refer to the help article Using HTTP / HTTPS Proxy with Cirrus Migrate Cloud for details.

Network Protocols

To maximize efficiency, Cirrus Migrate Cloud's outbound communication with Cirrus Data Cloud is in a binary http/2 (h2) protocol.

If your network environment (including firewall, https proxy, etc.) does not support or restricts http/2, you can add -no-http2 flag to the installation command. This flag will direct CMC to Cirrus Data Cloud network traffic to an alternative http/1.1 endpoint (

See Network Requirements for Cirrus Migrate Cloud Installation for more details

Updated on: 11/07/2022

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