PFSense issue with Intel 82576 dual link network cards

Question

We are building some firewalls that run PFSense. The systems use the SuperMicro Super X8DTN+ motherboard, which includes a dual link intel gigabit network card (Intel 82576 controller)

I have tried this out on several different identical boxes -- always the same result.

Anyway, if I configure PFSense to use the IGB driver for the intel 82576 and I setup one port of the dual port controller to be WAN and the other to be LAN I get terribly slow speeds (about 10 kB/sec). This with wan=igb0, lan=igb1

If I add an additional, separate PCI-X network card (using the EM driver) i get phenomenal speeds (wan=em0, lan=igb0). Kicker is -- the igb driver is still in use!

Any ideas why this might be or how to go about fixing it?

Answer 1

It turns out that there is a bug in the IGB driver as it relates to Large Receive Offloading (LRO).

Disabling LRO fixes the above described issue.

Simply:

echo "dev.igb.0.enable_lro=0" >>/etc/sysctl.conf echo "dev.igb.1.enable_lro=0" >>/etc/sysctl.conf

And reboot.

Everything works fine thereafter.