Re: [IETFMIBS] Extending InetAddress(Type) for BGP Multicast VPNs

[Juergen Schoenwaelder <[e-mail]>]

On Mon, Jan 09, 2012 at 12:40:19PM -0800, Jeff Haas wrote:
> I am the current editor for the BGP MIB (draft-ietf-idr-bgp4-mibv2).  I've been approached recently about MIB representation of BGP Multicast VPNs (draft-ietf-l3vpn-2547bis-mcast-bgp).  After having spent some time discussing this with some people internally at Juniper, it seems like the BGP MIBv2 would handle a significant portion of representing MVPNs.  This is great, because much of the purpose of the structure of the new BGP MIB was to make it re-usable for other address families.
> 
> The one sticking point is the representation of MVPN reachability (prefixes, effectively).  The BGP MIB does the following:
> 
> 
>     bgp4V2NlriPrefixType OBJECT-TYPE
>         SYNTAX     InetAddressType
>         MAX-ACCESS not-accessible
> 
> 
>         STATUS     current
>         DESCRIPTION
>             "The type of the IP address prefix in the
>              Network Layer Reachability Information field.
>              The value of this object is derived from the
>              appropriate value from the bgp4V2NlriAfi field.
>              Where an appropriate InetAddressType is not
>              available, the value of the object must be
>              unknown(0)."
>         ::= { bgp4V2NlriEntry 4 }
> 
>     bgp4V2NlriPrefix OBJECT-TYPE
>         SYNTAX     InetAddress
>         MAX-ACCESS not-accessible
>         STATUS     current
>         DESCRIPTION
>             "An IP address prefix in the Network Layer
>              Reachability Information field. This object
>              is an IP address containing the prefix with
>              length specified by bgp4V2NlriPrefixLen.
>              Any bits beyond the length specified by
>              bgp4V2NlriPrefixLen are zeroed."
>         REFERENCE
>             "RFC 4271, Section 4.3<http://tools.ietf.org/html/rfc4271#section-4.3>."
>         ::= { bgp4V2NlriEntry 5 }
> 
>     bgp4V2NlriPrefixLen OBJECT-TYPE
>         SYNTAX     InetAddressPrefixLength
>         MAX-ACCESS not-accessible
>         STATUS     current
>         DESCRIPTION
>             "Length in bits of the address prefix in
>              the Network Layer Reachability Information field."
>         ::= { bgp4V2NlriEntry 6 }
> 
> 
> It would seem that the "relatively simple" method to extend this to MVPN would be to update the InetAddress(Type) textual conventions.
> 
> I am aware that by making that statement I have stepped into the dragon's maw.  Please be gentle. :-)
> 
> But more seriously, this seems to be a good fit for what this TC was intended to accomplish: Make MIB structure more generic and reusable.  How could we go about accomplishing the goal of re-using the BGP MIB for MVPN?

I have no clue what change you think is needed. Please excuse my
ignorance of BGP Multicast VPNs - but for me it is easier to
understand what you propose to change if there is a more concrete
description of the change you envision.

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: [phone]         Campus Ring 1, 28759 Bremen, Germany
Fax:   [phone]         <http://www.jacobs-university.de/>