Frequently Asked Questions

From OpenFlow Wiki

FAQ

Q: When I go to insmod, I get "error inserting 'datapath/linux-2.6/ofdatapath.ko': -1 Unknown symbol in module".

A: Check dmesg output. If you get something like

"openflow_mod: Unknown symbol br_handle_frame_hook"

... then bridging is not enabled in the kernel you're using. The modinfo command may help here. With bridging enabled, expect something like this:

openflow: OpenFlow switching datapath implementation
openflow: v0.1.5 built on Feb  4 2008 08:01:55
openflow: Copyright (c) 2007 The Board of Trustees of The Leland Stanford Junior University
openflow: hijacking bridge hook

Q: When running the veth_setup script on CentOS, I get 'Command "add" is unknown, try "ip link help".'

A: Your version of IP Tables is too old. Read the CentOS install instructions to install a newer kernel and install iproute2 from source.