OPNsense Forum

Archive => 16.1 Legacy Series => Topic started by: bringha on January 31, 2016, 06:58:37 pm

Title: Hardware CRC checkbox in System->Einstellungen->Network
Post by: bringha on January 31, 2016, 06:58:37 pm

I have a question wrt the checkbox 'Disable Hardware CRC offloading' in System->Einstellungen->Network. CRC Hardware offloading is indeed a known issue with some NIC drivers when Freebsd runs as XEN HVM. The issue manifests in almost zero throughput through Opnsense from any other VM and dom0. I would have assumed that the idea behind setting this box should fix the known NIC driver problem

In the (new extended) documentation it is also recommended to tick the checkbox when installing Opnsense as a VM. At least for my native XEN installation,  this setting has no effect except a slightly higher CPU load, while traffic ist still almost none.

After a lot of forum research and experimenting around when installing opnsense, the break through came when  CRC offloading has been configured for the vif between dom0 and opnsense on the dom0 side in tx direction. If  CRC offloading is not configured for the direction, then only less then 1k bit throughput can be seen to any VM through Opnsense. Why is still not really clear to me ....

Im still looking for a concept that this setting is automatically done when opnsense is booting.  Up to now, I still have to launch an ethtool command manually on the dom0 side after each reboot

Does anybody has different experiences with a XEN installation for this or has solved the booting problem?

Looking forward to your reply.

Br br