Hi Alia,

Alia Atlas <[email protected]> writes:

> Hi Lada,
>
> The draft you mention is certainly of interest - particularly if I2RS
> requirements for a data modeling language result in selecting YANG.
>
> A couple quick points on your comments though.
>
> The next-hops are largely the POINT of this info-model.   The organization
> into route-tables and then route-instances allow different ones to be
> applied to different interfaces and such.  So, saying that the nexthops can
> be easily added via augmentation is saying that a very key feature is not
> yet there.  Similarly, the event notifications are also a key point of the
> info-model ; that is how different i2rs clients can learn dynamic
> information.

As I said, the two notifications will be added in the next revision. However, 
it is important to note that, by design, the data model in routing-cfg is 
mainly a skeleton or framework providing placeholders for real stuff (routing 
protocol or route filter data) to be filled in. As a proof of concept, I can 
certainly try to write a YANG module that augments the specific items defined 
in i2rs-rib-info-model, should you find this exercise useful.

>
> Having a comparison and thinking about how to extend the existing YANG
> model is certainly interesting - but I think it's important to get and
> agree on the info-model first.

The text of the routing-cfg draft in fact presents an information model, and in 
a very similar structure as the present draft (routing/router instances, 
routing tables, routes, but in addition also routing protocol instances and 
route filters). I think we should be able to agree on a common information 
model, even if the I2RS WG decides to use something else than YANG for data 
modelling.

>
> It's also clear that there are large critical aspects that are missing and
> needed (from the I2RS perspective).

>From the NETMOD perspective, these critical aspects are eagerly waiting to be 
>augmented into the existing YANG data model. :-)

Lada
 
>
> Alia
>
>
> On Wed, Jun 26, 2013 at 8:42 AM, Ladislav Lhotka <[email protected]> wrote:
>
>> Hi,
>>
>> this work, or at least its general parts, is closely related to the
>> following work item of the NETMOD WG:
>>
>> http://tools.ietf.org/html/draft-ietf-netmod-routing-cfg-09
>>
>> I tried to compare these two documents, and IMO the match is pretty good.
>> Paradoxically, the match would be even better if we take one of the
>> previous revisions of the routing-cfg documents because some constraints
>> that were originally present have been relaxed in the meantime (details
>> follow).
>>
>> I think it would make a good sense to coordinate these two efforts, and it
>> should't be difficult.
>>
>> Specific comments:
>>
>> 1. What you call "routing instance" is very similar to "router (instance)"
>> in routing-cfg. Interfaces are also assigned to each router instance, but
>> we don't require (since rev. -03) that the sets of interfaces assigned to
>> different router instances be disjoint. One use case is that two router
>> instances may be used for different address families, e.g., instance A for
>> IPv4 and B for IPv6. Then the same interface may be used in A for IPv4
>> traffic and in B for IPv6. Perhaps this also depends on the definition of
>> "interface".
>>
>> 2. Until rev. -05, each routing table was also confined to one router
>> instance. This was relaxed based on the following comment of a Routing
>> Directorate reviewer (Thomas Morin):
>>
>> "Allowing multiple "routers" is a good starting point for using these
>> specs in the context of RFC4364
>> (MPLS/BGP IP VPNs). However, if I understand correctly Yang syntax, the
>> way the filters are defined would
>> not work in the context of RFC4364, where a BGP routing instance in the
>> master "router" exports selected
>> routes in each of the routing table of each VPN (VRF).  The VRF also
>> export routes to the master
>> instance."
>>
>> 3. Route attributes, nexthops etc., as specified in
>> draft-nitinb-i2rs-rib-info-model-00, can be easily added into the YANG data
>> model via augmentation. We expect this will be done by future YANG modules
>> defining data models for routing protocols, such as BGP. For example, an
>> entry like your ISO_SYSTEM_ID can be augmented by an IS-IS module.
>>
>> 4. The data model in routing-cfg doesn't define any event notifications
>> yet, though I think there have already been some proposal. I think we can
>> add the two that you mention in sec. 5.
>>
>> 5. Routing tables can be inspected in the same way as other operational
>> state data, i.e., via the standard NETCONF operation <get>. However, we
>> also have two special RPC operations:
>>
>>    o  active-route: query the routing system for the active route(s)
>>       that are currently used for sending datagrams to a destination
>>       host whose address is passed as an input parameter.
>>
>>    o  route-count: retrieve the total number of entries in a routing
>>       table.
>>
>>
>> Cheers, Lada
>>
>>
>> Nitin Bahadur <[email protected]> writes:
>>
>> > Folks,
>> >
>> >   We have just posted an initial version of the RIB information model.
>> > Looking for feedback and collaborators who can help improve/add-to the
>> > draft.
>> >
>> > Thanks
>> > Nitin
>> >
>> >
>> > On 6/25/13 11:47 AM, "[email protected]" <
>> [email protected]>
>> > wrote:
>> >
>> >>
>> >>A new version of I-D, draft-nitinb-i2rs-rib-info-model-00.txt
>> >>has been successfully submitted by Nitin Bahadur and posted to the
>> >>IETF repository.
>> >>
>> >>Filename:      draft-nitinb-i2rs-rib-info-model
>> >>Revision:      00
>> >>Title:                 Routing Information Base Info Model
>> >>Creation date:         2013-06-25
>> >>Group:                 Individual Submission
>> >>Number of pages: 21
>> >>URL:
>> >>
>> http://www.ietf.org/internet-drafts/draft-nitinb-i2rs-rib-info-model-00.tx
>> >>t
>> >>Status:
>> >>http://datatracker.ietf.org/doc/draft-nitinb-i2rs-rib-info-model
>> >>Htmlized:
>> >>http://tools.ietf.org/html/draft-nitinb-i2rs-rib-info-model-00
>> >>
>> >>
>> >>Abstract:
>> >>   Routing and routing functions in enterprise and carrier networks are
>> >>   typically performed by network devices (routers and switches) using a
>> >>   routing information base (RIB).  Protocols and configuration push
>> >>   data into the RIB and the RIB manager install state into the
>> >>   hardware; for packet forwarding.  This draft specifies an information
>> >>   model for the RIB, to build a standardized RIB model, using which an
>> >>   external entity (external to the network device) can read and write
>> >>   information from/to the RIB.
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>The IETF Secretariat
>> >>
>> >>
>> >>
>> >
>> >
>> >
>> > _______________________________________________
>> > i2rs mailing list
>> > [email protected]
>> > https://www.ietf.org/mailman/listinfo/i2rs
>>
>> --
>> Ladislav Lhotka, CZ.NIC Labs
>> PGP Key ID: E74E8C0C
>> _______________________________________________
>> i2rs mailing list
>> [email protected]
>> https://www.ietf.org/mailman/listinfo/i2rs
>>
> _______________________________________________
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-- 
Ladislav Lhotka, CZ.NIC Labs
PGP Key ID: E74E8C0C
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