Re: [netmod] AD review of draft-ietf-netmod-system-mgmt

[Martin Bjorklund <[e-mail]>]

Benoit Claise <[e-mail]> wrote:
> Dear authors,
> 
> Here is my AD review.
> 
> -
> exactly like indraft-ietf-netmod-interfaces-cfg
> <https://datatracker.ietf.org/doc/draft-ietf-netmod-interfaces-cfg/>,
> which contains a summary table with MIB variable table, this document
> should contain a similar mapping table
> For example
>       +--rw system
>       |  +--rw contact?          string
>       |  +--rw hostname?         inet:domain-name
>       |  +--rw location?         string
>       +--ro system-state
>          +--ro platform
>             +--ro os-name?       string
>             +--ro os-release?    string
>             +--ro os-version?    string
>             +--ro machine?       string
> 
> This maps to the system group MIB variables. Some leavs definitions
> already refer to some MIB variables: sysContact, sysLocation, etc.
> I understand the MIB variables don't map 1:1, but telling that
>             os-name        part of the sysDescr MIB variable
>             os-release     part of the sysDescr MIB variable
>             os-version     part of the sysDescr MIB variable
>             machine?       part of the sysDescr MIB variable
> ... is also useful info.

For the 1-1 mapped object, we'll have this table:

                  +----------------+-------------------+
                  | YANG data node | SNMPv2-MIB object |
                  +----------------+-------------------+
                  | contact        | sysContact        |
                  | location       | sysLocation       |
                  +----------------+-------------------+


> Considering that NETCONF is now also used for monitoring, and that
> people were used to SNMP, such mapping tables would be a good practice
> in all NETMOD documents to help SNMP people/NMS make the transition.
> There might be some read-only MIB variables in the following RFCs:
> RFC 4668 RADIUS Authentication Client MIB

Our model provides parameters for configuring the radius client; this
MIB has objects for read-only monitoring.   The config objects affect
what is operationally used, but there is no 1-1 mapping.  The "related"
objects are:

 radius/server/transport/udp/udp/address
                 radiusAuthServerInetAddressType
                 radiusAuthServerInetAddress

 radius/server/transport/udp/udp/authentication-port
                 radiusAuthClientServerInetPortNumber

But I am not sure that listing these adds any value...?

> RFC 4669 RADIUS Authentication Server MIB

This is not applicable; we don't have any parameters for RADIUS
servers.

> RFC 5907 Definitions of Managed Objects for Network Time Protocol
> Version 4 (NTPv4)

Same situation as for the radius client.

> ...
> 
> So it needs a little bit of research, but shouldn't be too hard.
> 
> 
> -
>   leaf location {
>          type string;
>          description
>            "The system location. The server MAY restrict the size
>             and characters in order to maintain compatibility with
>             the sysLocation MIB object.";
>          reference
>            "RFC 3418 <http://tools.ietf.org/html/rfc3418>: Management
>            Information Base (MIB) for the
>                       Simple Network Management Protocol (SNMP)
>                       SNMPv2-MIB.sysLocation";
>        }
> 
> Question: do we want to be aligned with the leaf name logic
> inhttps://datatracker.ietf.org/doc/draft-ietf-netmod-interfaces-cfg/ ?
> 
> leaf name {
>    ...
>    In most cases, the "name" of an "interface" entry is mapped to
>    ifName. ifName is defined as a DisplayString [RFC2579] which uses a
>    7-bit ASCII character set.  An implementation that performs this
>    mapping MUST restrict the allowed values for "name" to match the
>    restrictions of ifName.
> 
> So basically
> NEW:
>   leaf location {
>          type string;
>          description
>            "The system location. In most cases, the "location" of an
>            "interface" entry
>            is mapped to sysLocation. sysLocation is defined as a DisplayString
>            [RFC2579]
>            which uses a 7-bit ASCII character set. An implementation that
>            performs this
>            mapping MUST restrict the allowed values for "location" to match
>            the
>            restrictions of sysLocation.";
>          reference
>            "RFC 3418 <http://tools.ietf.org/html/rfc3418>: Management
>            Information Base (MIB) for the
>                       Simple Network Management Protocol (SNMP)
>                       SNMPv2-MIB.sysLocation";
>        }

As Randy pointed out, the text above has some copy&paste errors.

OLD:

         The server MAY restrict the size and characters in
         order to maintain compatibility with the sysContact
         MIB object.";

NEW:

         This leaf MAY be mapped to the sysContact MIB object by an
         implementation.  Such an implementation MUST restrict the
         allowed values for this leaf so that it matches the
         restrictions of sysContact."

... but I am not convinced the new text is better than the old.  If
you think it is, I am fine with adding it.

(and same for location).



> +--rw system
>       |  +--rw clock
>       |  |  +--rw (timezone)?
>       |  |     +--:(timezone-location)
>       |  |     |  +--rw timezone-location?     ianatz:iana-timezone
>       |  |     +--:(timezone-utc-offset)
>       |  |        +--rw timezone-utc-offset?   int16
>       |  +--rw ntp!
>       |     +--rw enabled?   boolean
> 
>  leaf enabled {
>            type boolean;
>            default true;
>            description
>              "Indicates that the system should attempt
>               to synchronize the system clock with an
>               NTP server from the 'ntp/server' list.";
>          }
> 
> 
> How come that enabled is marked as optional while there is a default
> value?
> Aren't they slightly conflicting statements?
> Disclaimer: no strong feeling about that one.

It is optional to set for the client.

>  -
> Do we need the NTP version, 3 or 4, as a config field?

I saw that you answered this one yourself!


/martin