Xagent is an SSH authentication agent. Xagent keeps a record of every user key in Xshell user key database, and asks for the passphrase of a user key when it is required. When the passphrase of a user key is provided, Xagent decodes the user key and holds it in memory. Thus, using Xagent, you can use the same user key several times without entering the same passphrase repeatedly. Also, using agent forwarding feature of Xshell, other SSH clients on the remote machine can get access to the user keys held in Xagent.
Note: You can skip the 2nd step by selecting the Launch Xagent Automatically option in the SSH part of the Session dialog box. The Passphrase dialog box appears only if the status of the user key is Close. You can confirm the status of user keys in the Key List box of Xagent.
When using Xagent, remote SSH clients can use the private keys in Xshell. In other words, the remote host can use the keys that Xagent has. To use the user keys held in Xagent on the remote machine, the remote SSH server should support the agent forwarding feature.To enable agent forwarding feature of ssh.com server:
Note: OpenSSH servers automatically enable the agent forwarding feature unless user specifies the no-agent-forwarding option when they are started.
Note: If the SSH server supports the agent forwarding feature, the environment variable for agent forwarding (SSH_AUTH_SOCK or SSH2_AUTH_SOCK) is set to a proper value.