-----Original Message-----
From: Glenn Mansfield Keeni [mailto:[email protected]]
Sent: Tuesday, April 19, 2016 6:24 AM
To: Jeffrey (Zhaohui) Zhang; Benoit Claise; EXT - [email protected]
Cc: Mach Chen; [email protected]; Martin Vigoureux; [email protected]
Subject: Re: [bess] MIBDoc review of draft-ietf-bess-l2l3-vpn-mcast-mib-02.txt
Jeffrey,
Thanks for the update.
Will get back to you after a detailed review is done.
Glenn
On 2016/04/16 21:47, Jeffrey (Zhaohui) Zhang wrote:
Glenn,
Thanks for your comments. I've addressed most of your comments in the new
revision:
URL:
https://www.ietf.org/internet-drafts/draft-ietf-bess-l2l3-vpn-mcast-mib-03.txt
Status:
https://datatracker.ietf.org/doc/draft-ietf-bess-l2l3-vpn-mcast-mib/
Htmlized:
https://tools.ietf.org/html/draft-ietf-bess-l2l3-vpn-mcast-mib-03
Diff:
https://www.ietf.org/rfcdiff?url2=draft-ietf-bess-l2l3-vpn-mcast-mib-03
Please see below.
1. Abstract:
1.1 A sentence on how the managed objects will be used by
applications for operations, monitoring and management
would be good.
I had thought this would be standard/obvious for all MIB objects - the
read-write ones are used to control how a device works, and the read-only ones
are used for monitoring. Do I really need to say it explicitly?
I see RFC 4382 has the following:
This memo defines a portion of the Management Information Base
(MIB)
for use with network management protocols in the Internet community.
In particular, it describes managed objects to configure and/or
monitor Multiprotocol Label Switching Layer-3 Virtual Private
Networks on a Multiprotocol Label Switching (MPLS) Label Switching
Router (LSR) supporting this feature.
Is it enough to say something similar? For example:
In particular, it describes common managed objects used to
configure
and/or monitor both L2 and L3 VPN Multicast.
2. Introduction
2.1 Please give the full expansion of the abbreviations
appearing for the first time. (PE, VPLS,..)
Fixed.
2.2 The terminology section is a bit terse. Explaining the
terms that are used, nicely with reference to the protocol
documents will improve readability.
e.g.
- PMSI, I-PMSI, S-PMSI, provider tunnels
As the paragraph alluded to, this MIB needs to be understood in the general
context of L2/L3 multicast VPN and providing good explanation of the terms is
not attempted. The references for the terms are the the RFCs for the relevant
technologies.
Having said that, I'll explain PMSI a bit further.
2.3 Is there a difference between
"multicast in Layer 2 and Layer 3 VPNs , defined by
RFC 7117 and RFC 6513/6514"
used in the DESCRIPTION in the MODULE-IDENTITY
and
"multicast in BGP/MPLS L2 or IP VPN"
used in the DESCRIPTION of L2L3VpnMcastProviderTunnelType ?
If these are the same, it will be helpful to stick to the
same expression. If these are not the same, the dictinction
should be clarified.
No difference. I was using "Layer 3" or "L3" but it was pointed out that the
layer 3 VPN is often referred to IP VPN in other RFCs and I was advised to
change it accordingly. Looks like I did not change all the cases.
On the other hand, I noticed that RFC 4382 does use "Layer 3 VPN" so I'll
change it back.
3. Summary of MIB Module.
An overview of the L2L3-VPN-MCAST-MIB will be good- the
structure of the MIB, short descriptions of the table(s)
including usage of the table(s) for management and/or by
other MIB(s).
I had that, but have added one sentence about the only table.
MIB definitions:
4. MIB syntax checking:
smilint -s -e -l 5 mibs/L2L3-VPN-MCAST-MIB
2>L2L3-VPN-MCAST-MIB.txt
I used simpleweb's validation tool but looks like I did not use the strictest
level of validation. I've now fixed the following issues and verified.
mibs/L2L3-VPN-MCAST-MIB:63: [4] {hyphen-in-label} warning: named
number `rsvp-p2mp' must not include a hyphen in SMIv2
mibs/L2L3-VPN-MCAST-MIB:64: [4] {hyphen-in-label} warning: named
number `ldp-p2mp' must not include a hyphen in SMIv2
mibs/L2L3-VPN-MCAST-MIB:65: [4] {hyphen-in-label} warning: named
number `pim-asm' must not include a hyphen in SMIv2
mibs/L2L3-VPN-MCAST-MIB:66: [4] {hyphen-in-label} warning: named
number `pim-ssm' must not include a hyphen in SMIv2
mibs/L2L3-VPN-MCAST-MIB:67: [4] {hyphen-in-label} warning: named
number `pim-bidir' must not include a hyphen in SMIv2
mibs/L2L3-VPN-MCAST-MIB:68: [4] {hyphen-in-label} warning: named
number `ingress-replication' must not include a hyphen in SMIv2
mibs/L2L3-VPN-MCAST-MIB:69: [4] {hyphen-in-label} warning: named
number `ldp-mp2mp' must not include a hyphen in SMIv2
See later question/comments below.
mibs/L2L3-VPN-MCAST-MIB:215: [5] {group-unref} warning: current
group `l2L3VpnMcastOptionalGroup' is not referenced in this module
mibs/L2L3-VPN-MCAST-MIB:4: [5] {import-unused} warning: identifier
`NOTIFICATION-TYPE' imported from module `SNMPv2-SMI' is never used
mibs/L2L3-VPN-MCAST-MIB:5: [5] {import-unused} warning: identifier
`Unsigned32' imported from module `SNMPv2-SMI' is never used
mibs/L2L3-VPN-MCAST-MIB:8: [5] {import-unused} warning: identifier
`NOTIFICATION-GROUP' imported from module `SNMPv2-CONF' is never used
mibs/L2L3-VPN-MCAST-MIB:11: [5] {import-unused} warning: identifier
`TruthValue' imported from module `SNMPv2-TC' is never used
mibs/L2L3-VPN-MCAST-MIB:11: [5] {import-unused} warning: identifier
`RowStatus' imported from module `SNMPv2-TC' is never used
mibs/L2L3-VPN-MCAST-MIB:12: [5] {import-unused} warning: identifier
`TimeStamp' imported from module `SNMPv2-TC' is never used
mibs/L2L3-VPN-MCAST-MIB:12: [5] {import-unused} warning: identifier
`TimeInterval' imported from module `SNMPv2-TC' is never used
mibs/L2L3-VPN-MCAST-MIB:15: [5] {import-unused} warning: identifier
`SnmpAdminString' imported from module `SNMP-FRAMEWORK-MIB' is never
used
mibs/L2L3-VPN-MCAST-MIB:18: [5] {import-unused} warning: identifier
`InetAddress' imported from module `INET-ADDRESS-MIB' is never used
mibs/L2L3-VPN-MCAST-MIB:18: [5] {import-unused} warning:
identifier `InetAddressType' imported from module `INET-ADDRESS-MIB'
is never used
Removed the above unused imports.
5. REFERENCE clauses: Please use REFERENCE clauses liberally.
Wherever possible, provide references for objects used in
the MIB. The references will point to specific sections/
sub-sections of the RFCs defining the protocol for which the
MIB is being designed. It will greatly improve the readability
of the document.
Added.
6. IMPORTS clause
MIB modules from which items are imported must be cited and
included in the normative references.
The conventional style is
mplsStdMIB
FROM MPLS-TC-STD-MIB --
[RFC3811]
Added.
7. Please update the MODULE-IDENTITY. (There are no syntantic
errors.)
7.1 CONTACT-INFO
Following the conventions (including indentation style) will
improve the readability. (e.g. RFC4382, RFC5132).
Will be good if it does not overflow into the next page.
Fixed.
7.2 REVISION clause: follow the convention recommended in RFC4181
sec 4.5
REVISION "200212132358Z" -- December 13, 2002
DESCRIPTION "Initial version, published as RFC yyyy."
-- RFC Ed.: replace yyyy with actual RFC number & remove this note:
Fixed.
7.3 OID assignment: follow the convention recommended in RFC4181
sec 4.5 i
replace
::= { experimental 99 } -- number to be assigned
by
::= { <subtree> XXX }
-- RFC Ed.: replace XXX with IANA-assigned number & remove this note
<subtree> will be the subtree under which the module will be
registered.
I kept "experimental 99" so that I could continue to use mib tools to validate;
but I added notes for the editor to replace them as you indicated.
8. Specific MO and TC related comments.
L2L3VpnMcastProviderTunnelType ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Types of provider tunnels used for multicast in
BGP/MPLS L2 or IP VPN."
SYNTAX INTEGER { unconfigured (0),
rsvp-p2mp (1),
ldp-p2mp (2),
pim-asm (3),
pim-ssm (4),
pim-bidir (5),
ingress-replication (6),
ldp-mp2mp (7)
o Would be nice to align the enumeration labels with the
labels in the protocol document RFC 6514 unless there is
a good reason for not doing so. (You will have to take
care of the smi compilation errors too; '-' is not allowed ).
Are spaces allowed? I don't know so I used hyphen. For now I replace with
things like rsvpP2mp.
Or could/should I just remove the definitions, so that if a new type is defined
in the future there is no need to update the MIB?
8.1 l2L3VpnMcastPmsiTunnelAttributeEntry OBJECT-TYPE
SYNTAX L2L3VpnMcastPmsiTunnelAttributeEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in this table corresponds to an PMSI attribute
that is advertised/received on this router.
For BGP-based signaling (for I-PMSI via auto-discovery
procedure, or for S-PMSI via S-PMSI A-D routes),
they are just as signaled by BGP (RFC 6514 section 5,
'PMSI Tunnel attribute').
For UDP-based S-PMSI signaling for PIM-MVPN,
they're derived from S-PMSI Join Message
(RFC 6513 section 7.4.2, 'UDP-based Protocol')..
Note that BGP-based signaling may be used for
PIM-MVPN as well."
o Fix the ".." in "'UDP-based Protocol').." above.
o Please give the reference for this Table.
Is it- "PMSI Tunnel attribute" in RFC 6513 Sec.4 ?
"PMSI Tunnel attribute" in RFC 6514 Sec.5 ?
both?
Any other pointers?
Fixed.
8.2 l2L3VpnMcastPmsiTunnelAttributeFlags OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (1))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"For UDP-based S-PMSI signaling for PIM-MVPN, this is 0.
For BGP-based I/S-PMSI signaling, this is the Flags
field in PMSI Tunnel Attribute of the corresponding
I/S-PMSI A-D route."
::= { l2L3VpnMcastPmsiTunnelAttributeEntry 1 }
o Please confirm that the above is a complete enumeration of the
types of signalling.
o RFC 6514 Sec.5 says that the Flags field indicates
"Leaf Information Required". That is useful information.
Please include in the description.
The intent is to simply return the octet value of the flags field, w/o listing
individual bits like "Leaf Information Required". More bits could be defined in
the future but the MIB would not change.
Is that OK?
8.3 l2L3VpnMcastPmsiTunnelAttributeId OBJECT-TYPE
SYNTAX OCTET STRING ( SIZE (0..37) )
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"For UDP-based S-PMSI signaling for PIM-MVPN, the first
four or sixteen octets of this attribute are filled with
the provider tunnel group address (IPv4 or IPv6)..
For BGP-based I/S-PMSI signaling, this is the Tunnel
Identifier
Field in PMSI Tunnel Attribute of the corresponding
I/S-PMSI
A-D route."
o Check the size specifications. The specs above say it can be
all sizes 0..37. That is not clear from the DESCRIPTION clause.
o Fix the ".." in "(IPv4 or IPv6).." above.
o RFC 6514 Sec 5. PMSI Tunnel Attribute gives the Tunnel Identifiers
for mLDP, PIM-SM, PIM-SSM, BIDIR-PIM,Ingress
Replication,MP2MP.
It appears that the sizes (range) for each case will be different.
Please clarify that, and if there are discrete sizes, specify
accordingly.
Depending on the tunnel type, there could be different sizes. Future tunnel
types could have other sizes that not specified today. I was thinking to just
give
a size range so that it is flexible. Is that ok?
8.3 l2L3VpnMcastPmsiTunnelPointer OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"If the tunnel exists in some MIB table, this is the
row pointer to it."
o "some MIB table" : specify which MIB table.
I can give an example, like mplsTunnelTable [RFC 3812]. It could be whatever
table that a tunnel may be put into.
o In what case will the tunnel exist and in what case will it not?
If a device supports mplsTunnelTable and the tunnel is represented there,
then it exists.
o What will be the behaviour if the above condition is not satisfied?
A null pointer should be given.
8.4 l2L3VpnMcastPmsiTunnelIf OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"If the tunnel has a corresponding interface, this is the
row pointer to the ifName table."
o DESCRIPTION looks incorrect. Please fix it. Do you want to say
this object points to the corresponding row in the ifTable?
Yes. Fixed.
o In what case does the TunnelIf exist and in what case will it not?
Some tunnels may not have a corresponding interface.
o What will be expected if the tunnel does not have a corresponding
interface?
Null row pointer.
9. The Security Considerations section does not follow the Security
Guidelines for IETF MIB Modules
http://trac.tools.ietf.org/area/ops/trac/wiki/mib-security.
Please fix.
I was really hoping that it would not have to be that tedious. SNMP/MIB
security should be no different from the CLI security - once you secure the
infrastructure then what's more to do?
I'll need more time to work on this. Let me try to address the issues in the
other mib first and come back to this.
10.ID-nits
10.1 Checking nits according to http://www.ietf.org/id-info/checklist :
---------------------------------------------------------------------
------
** There are 4 instances of too long lines in the document, the
longest one
being 3 characters in excess of 72.
I fixed some but there still three too long lines:
l2L3VpnMcastPmsiTunnelAttributeType
L2L3VpnMcastProviderTunnelType,
l2L3VpnMcastGroups OBJECT IDENTIFIER ::=
{l2L3VpnMcastConformance 1}
l2L3VpnMcastCompliances OBJECT IDENTIFIER ::=
{l2L3VpnMcastConformance 2}
Should I break them into different lines or just keep them as is? Any example
of expected indentation if I break the lines?
10.2 Checking references for intended status: Proposed Standard
---------------------------------------------------------------------
------
== Missing Reference: 'RFC 7117' is mentioned on line 76, but not
defined
'described in [RFC6513, RFC6514, RFC 7117] and other
documents tha...'
I hope I understood and fixed it (removing the space in "RFC 7117").
11. There is another WIP MVPN-MIB in draft-ietf-bess-mvpn-mib-02.txt
MVPN-MIB has objects that refer to L2L3-VPN-MCAST-MIB.
Is there a good reason for not merging the 2 documents? I have not
seen
any discussion or explanation on this. I may have missed it. Please
clarify or, give some pointers.
As mentioned in the introduction:
this memo describes managed objects common to both VPLS
Multicast [RFC7117] and MVPN [RFC6513, RFC6514].
MVPN-MIB is for MVPN. There was another VPLS Multicast MIB in the work
and both would reference common objects defined in this MIB.
Thanks!
Jeffrey
-----Original Message-----
From: BESS [mailto:[email protected]] On Behalf Of Glenn
Mansfield Keeni
Sent: Tuesday, April 12, 2016 2:28 AM
To: Benoit Claise <[email protected]>; EXT - [email protected]
<[email protected]>
Cc: Jeffrey (Zhaohui) Zhang <[email protected]>; [email protected];
Martin Vigoureux <[email protected]>; [email protected]; Mach
Chen <[email protected]>
Subject: [bess] MIBDoc review of
draft-ietf-bess-l2l3-vpn-mcast-mib-02.txt
Hi,
I have been asked to do a MIB Doctors review of
draft-ietf-bess-l2l3-vpn-mcast-mib-02.txt.
My knowledge of L2L3VPN Multicast is limited to the reading of this
document and browsing through the documents referred to in the draft
and bess-wg mailing list archives.( read "shallow").
So some of the doubts and questions may sound trivial or strange.
Please bear with me and help me help you make this into a better
document :-)
The comments are attached.
Glenn
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