I frequently run into scenarios where two devices (two routers, or a router and a host) need a point-to-point connection to each other with a capacity of (much) more than 10 Gbps. For cost reasons, Ethernet is often used. Since more than 10 Gbps is needed, we end up with multiple parallel 10GE point-to-point connections. Because the devices often don't support LAG or have limitations on the number of links in a LAG, we often cannot use LAG at all or cannot put all 10GE links in a single LAG group. So, we end up with multiple parallel layer-3 point-to-point connections where each connections is either an Ethernet or a LAG group. Furthermore, in order to conserve IP addresses, there is a desire to make these interfaces unnumbered. The involved devices have a numbered loopback interface whose address is used as the "donor" for the unnumbered Ethernet / LAG interfaces. Most router vendors already support unnumbered point-to-point Ethernet, see for example: http://www.juniper.net/techpubs/en_US/junos9.5/information-products/topic-co... However, there are some interoperability issues / open questions related to point-to-point unnumbered Ethernet, see for example: http://forums.juniper.net/jnet/board/message?board.id=JUNOS&message.id=130 http://forums.juniper.net/jnet/board/message?board.id=switch&thread.id=835 I would be very interested in some standards (i.e. an IETF BCP) to describe the best current practices for these applications of Ethernet. I am not particularly interested in re-inventing a new flavor of Ethernet for this application. All that is needed, in my opinion, is some clarifications or best practices on how to use the existing standards to create point-to-point unnumbered Ethernet connections. PS -- I am also aware of some esoteric BRAS applications of Ethernet where one side is numbered and the other side is unnumbered.