TUNNEL_ERROR when trying to vnc from browser


with fireedge endpoints activated in /etc/one/sunstone-server.conf, when I try to vnc to a VM from webbrowser, I get a message “TUNNEL_ERROR”. Unfortunately, the error does not appear in sunstone.log, fireedge.{log,error} or novnc.log, so that I cannot get detailed information about what is going wrong. The only unusual thing in my configuration is that I am using lighttpd to proxy the traffic over ssl, and I am quite sure that all required ports are not blocked by a firewall.

The following lines in my fireedge-server.conf define the ip and port to listen on:

host: ‘’
port: 2615

These two lines in my sunstone-server.conf define the fireedge endpoints:

:private_fireedge_endpoint: http://localhost:2615
:public_fireedge_endpoint: https://www.example.com:2616

lighthttpd proxies request to port 2616 to port 2615.

Any ideas what is wrong?


I am having this issue as well. I am using nginx as a reverse proxy. I can’t seem to find a log entry explaining what the error is having an issue with.

Ok looks like the issue is the proxy.

console errors in the web browser lead to a wss error.

The key is to merge into the ngnix conf for /fireedge the guacamole reverse proxy bits from the guacamole documentation

The nginx reverse proxy examples on this forum are for the pre 6 versions that were focused on novnc and didn’t have the guac bits:

proxy_buffering off;
proxy_http_version 1.1;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $http_connection;
access_log off;