Cayle, This may be partial hijack of the thread or even a trivial query but I ask this since you mentioned "For cost reasons, Ethernet is often used". We hear this argument all the time. The standard unabridged reason I have learned is the ubiquity of Ethernet devices, whatever that means. Can you say why precisely the cost of Ethernet is low compared to other viable alternatives? Zartash On Thu, Jul 9, 2009 at 7:29 PM, Cayle Spandon <cayle.spandon@gmail.com>wrote:
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.