This article explains the reason for JSA blocking direct SSH connections to a managed host.

SSH connections to managed hosts are refused.

Consoles and unmanaged hosts allow SSH from any inbound request. However, when a host is added to the deployment, the consoles allow SSH access only from the JSA Console, and the console keeps port 22 open for inbound connections.

The reason is to secure communication between the console and managed hosts. The console connects to the managed hosts using an encrypted SSH session to communicate securely. These SSH sessions are initiated from the console to provide data to the managed host.

You can limit the inbound connections on port 22 by modifying a host's iptables rules. Iptables on Event Processor (EP) / Flow Processor (FP) boxes restrict outside SSH access.

In a distributed JSA deployment where you have one console and many Event/ Flow collectors, you can SSH only to the console. To log in to Event Processor/Flow Processor using SSH, you need to first SSH to the console and from there SSH to the managed hosts.

2020-12-28: Modified article to include reason for direct SSH access to managed hosts being restricted