Overview

This article can be used when you are unable to scan Linux distribution systems showing the error Protocol major versions differ for IP and port <number> SSH-2.0-OpenSSH_7.4 vs. SSH-1.5-LNSS.

Topics covered in corresponding support articles:

• What are the requirements to scan and patch Linux computers with GFI LanGuard?

• What Linux operating systems are supported for patching in GFI LanGuard?

Environment

• GFI LanGuard
• All support versions

Root Cause

• The Linux Distribution system is having an older or different installed protocol for SSH.
• GFI LanGuard has not replaced the old files after the upgrade and is using an outdated protocol SSH version.
• Protocol major versions differ for IP address and port number SSH 2.0 OpenSSH-7.4 vs. SSH-1.5 LNSS.

Resolution

1. Verify that the GFI LanGuard installer.exe file is unblocked from Properties in the General tab.
2. Test the connectivity from LanGuard to Linux using putty.
3. Remove the client from LanGuard Dashboard and re-add the client again and re-scan.
4. Check the SSH protocol version on the Linux distribution system, update if outdated.

Note: If the Linux distribution system is having the SSH version up-to-date and connectivity test is fine from LanGuard to the client. Do a reinstallation of LanGuard and verify it.

Confirmation

Once you successfully complete the above steps, You will now be able to scan Linux distributed systems without any error message.