Re: [nvo3] VRF text (take 3) in draft-narten-nvo3-overlay-problem-statement-02.txt

["Luyuan Fang (lufang)" <[e-mail]>]

Benson, Thomas, and David,

As some of us have gone through the ppvpn/l3vpn development in the last decade are familiar with the history around VR development in ppvpn/l3vpn, others may benefit with more clarification.

Two approaches were proposed initially: rfc 2547 BGP/MPLS VPN, and Virtual Router (VR) VPN. 2547 has been development and widely deployed, VR VPN solution did not progress to standard RFCs.
Thomas Morin has provided good summary of the differences between the two, and the status for each.

The base VR solution drafts and the VR applicability statement draft Benson referenced did not become RFCs. As IESG write-ups in 2006 indicated: "Active participation in the L3VPN WG on Virtual Routers has not existed for some time. There is little energy to modify these documents further,..."

So the fact remains there is no Virtual Router solution for l3vpn/l2vpn as Standard track RFCs, even though the informational RFC 4110 on Framework talked virtual router as it was published in 2005 before VR was ended.

Virtual Router term is often used in other context as general term. You can virtualize a physical router into multiple virtual routers with resource partition, some only has control plane partition, e.g. each can run separate IGP, BGP..., others may have HW resource partition as well. There are can be various levels of virtualization. We were discussing with vendors for virtual router/logical router starting 2000 when I was working in SP. E.g. virtual router/logical router could be considered to separate L3 VPN services and Internet services through resource partition, or make separate P and PE routers with resource partition using the same box, etc. all not much to do VPNs, it is general device virtualization. Many devices today can support pretty sophisticated virtualization.

I'm OK if you use the virtual router as generic term and explain the use case, and not to reference back to the VR VPN approach which is not IETF standards.

Luyuan


From: Benson Schliesser [mailto:[e-mail]]
Sent: Monday, July 09, 2012 4:28 PM
To: [e-mail]
Cc: Luyuan Fang (lufang); [e-mail]
Subject: Re: [nvo3] VRF text (take 3) in draft-narten-nvo3-overlay-problem-statement-02.txt


On 2012-07-06 8:35 AM, [e-mail]<mailto:[e-mail]> wrote:

Luyuan,



- "virtual routers" <> multiple VRFs on a router ... Could you

help us with the IETF reference if you think your "virtual router"

definition is correct?



Sure, "virtual router" is the correct term, a "virtual router" is definitely

not a VRF for a BGP/MPLS VPN and the term "virtual router" has been in use in

the IETF for well over a decade.



The two paragraphs in question were always intended to refer to the concept

of a "virtual router" as that term is used with VRRP, see RFC 5798, and the

use of "virtual router" dates back to at least the first version of VRRP,

RFC 2338 (1998).  In 20/20 hindsight, the use of the VRF acronym in those

two paragraphs was a mistake that we are now correcting - that mistake is

at the root of this confusion (mea culpa, as I'm a co-author of that original

text).  Do we need to cite RFC 5798 to make this clearer?

FYI, per http://tools.ietf.org/html/rfc4110#section-1.5 a Virtual Router is defined as:


   Virtual Router (VR): An instance of one of a number of logical
   routers located within a single physical router.  Each logical router
   emulates a physical router using existing mechanisms and tools for
   configuration, operation, accounting, and maintenance.

For more context, one might also wish to read http://tools.ietf.org/html/draft-ietf-l3vpn-as-vr-02 and some of its references.

Cheers,
-Benson