Troubleshooting 'GRE: Protocol not available' errors

By Ryan Roth

This article is designed to help troubleshoot the following error and other similar protocol 47(GRE) errors:

"GRE: read(fd=7,buffer=8056b60,len=8260) from network failed: status = -1 error = Protocol not available"

Below is a list of the most common causes I came across during my research on these errors.

#1. Client firewall:

#2. Server firewall

#3. Protocol 47 NOT port 47

#4. Patching kernel and recompiling.

Additional Resource:

Source Forge Project Page | Downloads | News | Mailing List
Free Software Foundation SourceForge Logo Valid HTML 3.2! Viewable With Any Browser