Rdesktop connection reset by peer is a common error when connecting to a remote windows server.

Usually, this error happens due to wrong settings in the rdesktop client related to authentication.

At Bobcares, we often get requests to fix rdesktop errors, as a part of our Server Management Services.

Today, let’s see how our Support Engineers fix “rdesktop connection reset by peer”

What is Rdesktop?

Basically, Rdesktop is open-source software that enables us to connect to remote windows server from Linux.

To connect to Windows host from Linux we use the command:

rdesktop -u <username> -p <password> <host:port>

We can also include a few parameters in the command to change the appearance of the windows host.

Causes for connection reset by peer

Let’s now check on what causes the connection reset error in the rdesktop.

By default, Windows server from and above Windows 2012 allows a connection that supports Network Level Authentication.

Network Level Authentication is a technology that requires a user to authenticate themselves before establishing a connection. As a result, it prevents the initiation of a full rdesktop connection before user authentication. Thus, it helps greatly to mitigate Remote Desktop vulnerabilities.

However, it brings in a lot of restrictions on the rdesktop clients. For instance, to use Network Level Authentication in Remote Desktop Services, the client must be running Windows XP SP3 or later.

So to connect from the Linux machine using rdesktop,  the Network level Authentication has to be disabled. Or else, the error message will appear as :

ERROR: send: Connection reset by peer
ERROR: Connection closed

Let’s now move on and see the workarounds to resolve the error.

How we fix it

Recently, we had a customer that was facing problems connecting to his Windows host from his Linux machine.

Let’s discuss how our Support Engineers disabled NLA and made the connection working.

Disable Network Level Authentication

First we login to the windows server from another windows server. Since the RDP supports Network Level Authentication, we disable the setting from :

Search systempropertiesremote.exe from start. A window appears and then click on the Remote tab.

Or Click Start >> Administrative Tools, and then click Server Manager.

In the left pane, expand Roles.

Expand Remote Desktop Services. Then click on Remote Desktop Session Host Configuration.

Deselect “Allow connections only from computers running Remote Desktop with Network Level Authentication”

For servers below Windows Server 2008, we select the option “Allow connections from computers running any version of Remote Desktop (less secure)”

Finally, we apply the changes.

Note: When the option is disabled the Network level authentication is skipped. Allowing connections using NLA is a more secure authentication method. It might even lead to a server attack as well.

Without disabling NLA

However, some customers may not have the option to disable NLA due to security reasons.

Without disabling NLA, the only option is to go for a rdesktop alternative that supports NLA. FreeRDP is a free remote desktop protocol client. Therefore, our Dedicated Engineers recommend the use of FreeRDP as one of the best alternatives for rdesktop that support NLA.

[Still getting a connection reset error in rdesktop? We can fix it for you.]

Conclusion

In short, we have discussed the common causes for the error “rdesktop connection reset by peer”. Also, we saw how our Support Engineers resolve the error by disabling NLA in the windows server.