Mark Smith wrote:

ETH_P_LOOP should probably have been avoided, as "LOOP" or "loopback"
is commonly used to refer to the Ethernet Configuration Testing
Protocol (google search for "Ethernet Loop protocol"). 

I wonder how that relates to linkloop:

http://sourceforge.net/projects/linkloop/

http://fr2.rpmfind.net/linux/RPM/opensuse/factory/x86_64/usr_share_doc_packages_linkloop_Tree.html

I'd suggest not using any form of ARP for this purpose. It'd place an
IPv4 requirement on the bonded interface, and various "empty" ARP
frames have meaning e.g. duplicate address detection. 802.2 test frames
or the original Ethernet V2.0 Configuration Testing Protocol have been
used for this bridge table address refresh purpose in the past.

I can never remember if linkloop uses XID or Test frames :(

rick jones