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Re: [Bridge-mib] VLAN-ID



Nope, not happy to ignore the IEEE's constraint.  If the IEEE reserve
a value for their object, we
should do the same.  Who knows what a Cisco or 3Com implementation
might do with it that we may wish later to model.  (More generally, it
was bad programming in the 1970s to 'borrow' a value from a range that
was not used at that moment in order to convey some additional
semantic, like invalid or escape; it was bad database design to do
that in the 1980s and by then we had formal methods to tell us it was
bad; it remains bad MIB design to do it now with SNMP).

Likewise, IEEE define this as unsigned so making it an Integer32 I
regard as
wrong.

And that reference; are we basing this on the draft work in progress
of
the IEEE, to which noone on these lists has yet admitted having
access, or on the published, 801.1Q 1998 standard (which I have in
front of me)?  We should, by liaising with the IEEE if no other
means, find out if the work in progress changes this part of the
specification.


Tom Petch
nwnetworks@dial.pipex.com

-----Original Message-----
From: Les Bell <Les_Bell@eur.3com.com>
To: Randy Presuhn <randy_presuhn@mindspring.com>
Cc: bridge-mib@ietf.org <bridge-mib@ietf.org>; mibs@ops.ietf.org
<mibs@ops.ietf.org>
Date: 24 February 2003 10:14
Subject: Re: [Bridge-mib] VLAN-ID
>
>If the "any" value is to be non-negative, then it should be 4095
>(0x0FFF), as suggested by Andrew Smith in an earlier email.  This
>value is reserved by 802.1Q-1998, in Table 9-2, with the following
>definition:
>
>  "Reserved for implementation use. This VID value shall not be
>   configured as a PVID, configured in any Filtering Database entry,
>   used in any Management operation, or transmitted in a tag header."
>
>There is a concern that it says "This VID value shall not be ...
>used in any Management operation ...", but this does not consider the
>need for a wildcard value.  Would everyone be happy to ignore this
>constraint?
>
>Les...
>
>"Randy Presuhn" <randy_presuhn@mindspring.com> on 24/02/2003 06:29:58
>
>Sent by:  "Randy Presuhn" <randy_presuhn@mindspring.com>
>
>To:   bridge-mib@ietf.org
>cc:   mibs@ops.ietf.org (Les Bell/GB/3Com)
>Subject:  Re: [Bridge-mib] VLAN-ID
>
>Hi -
>
>I think it would be better if the "any" value in the *OrAny TC were
>a non-negative value so that the type could be used to define an
>index.  There may not be a need today, but thinking ahead to
>representing policy-like things wouldn't hurt.
>
>Randy
>
>> From: "Wijnen, Bert (Bert)" <bwijnen@lucent.com>
>> To: "Romascanu, Dan (Dan)" <dromasca@avaya.com>;
<bridge-mib@ietf.org>
>> Cc: <mibs@ops.ietf.org>
>> Sent: Friday, February 21, 2003 7:15 AM
>> Subject: RE: [Bridge-mib] VLAN-ID
>>
>
>> Having seen some discussion. How about if we were to define
>> two generic TCs for this that people will be encouraged to use
>> from now on:
>>
>>
>>   VlanId            ::= TEXTUAL-CONVENTION
>>       DISPLAY-HINT "d"
>>       STATUS        current
>>       DESCRIPTION  "A 12-bit VLAN ID used in the VLAN Tag header."
>>       SYNTAX        Integer32 (1..4094)
>>       REFERENCE    "Draft Standard for Virtual Bridged Local Area
>>                     Networks, P802.1Q/D10, chapter 3.13
>>                    "
>>
>>   VlanIdOrAny       ::= TEXTUAL CONVENTION
>>       DISPLAY-HINT "d"
>>       STATUS        current
>>       DESCRIPTION  "The VLAN ID that uniquely identifies a VLAN.
>>                     The value of -1 is used to indicate a wildcard,
>>                     i.e. any value.
>>                    "
>>       SYNTAX        Integer32 (-1 | 1..4094)
>>
>> Or would the VlanIdOrAny better be represented with
>>       SYNTAX        Integer32 (-1 | 1..4094)
>> where zero represents the wild card ??
>>
>> Not sure if we should include the VlanIndex from RFC2674. I think
>> it is not as general... but am not sure. If we were to generalize
it,
>> then I would think it should look like:
>>
>>   VlanIndex         ::= TEXTUAL-CONVENTION
>>       DISPLAY-HINT "d"
>>       STATUS        current
>>       DESCRIPTION  "A value used to index per-VLAN tables:
>>                    - values of 0 and 4095 are not permitted;
>>                    - a value between 1 and 4094 inclusive
represents
>>                      an IEEE 802.1Q VLAN-ID with global scope
within
>>                      a given bridged domain (see VlanId textual
>>                      convention).
>>                    - a value greater than 4095 represents a VLAN
with
>>                      scope local to the particular agent, i.e. one
>>                      without a global VLAN-ID assigned to it. Such
>>                      VLANs are outside the scope of IEEE 802.1Q but
>>                      it is convenient to be able to include them in
>>                      tables in the same way.
>>                    "
>>       SYNTAX        Unsigned32 (1..4094 | 4096..4294967295)
>>
>> Or should we also use an Integer32 for the last one?
>> Would RFC2674 be the best place to define those?
>>
>> If we were to do the above, then
>> - the framework PIb can keep what they have. At a future revision
>>   they can pick up the TC
>> - RFC2613 could still advance as is.
>>   I would prefer a new one that uses the new TC, but that new
>>   TC will be in a PS, so that would prohibit advancing to DS.
>>   So we can do that at a later stage.
>> - RFC2674 gets updated
>> - docsis MIB probably should pick up new TC, or at least define
>>   their VlanID the same way as proposed in the TC.
>>
>> Thanks,
>> Bert
>>
>> > -----Original Message-----
>> > From: Romascanu, Dan (Dan) [mailto:dromasca@avaya.com]
>> > Sent: woensdag 19 februari 2003 18:57
>> > To: Wijnen, Bert (Bert); bridge-mib@ietf.org
>> > Cc: mibs@ops.ietf.org
>> > Subject: RE: [Bridge-mib] VLAN-ID
>> >
>> >
>> > Bert,
>> >
>> > I suggest to take the discussion to the mibs list. The
>> > interest is broader than Bridge MIB, as demonstrated by the
>> > number of MIBs that deal with VLAN ID objects.
>> >
>> > To the point:
>> > - It looks that definitions in
>> > draft-ietf-bridge-ext-v2-01.txt, RFC 2613 and RFC 2674
>> > (VlanId) are similar. A common TC can be easily defined, by
>> > taking the RFC 2674 VlanId TC and adding the REFERENCE as in
>> > RFC 2613.
>> > - I do not know what is the reason DOCSIS supports value 0.
>> > - The framework PIB have added a special value -1, with a
>> > separate semantics (ignore VLAN in the filter).
>> > - VlanIndex in RFC2674 also has a different semantics.
>> >
>> > Side issue -  if a TC can be easily written and agreed (after
>> > some cat beating) - what will we be doing with documents
>> > already on the standards track? RFC 2613 is supposed to be
>> > advanced from PS to DS 'as is'. You can buy a beer to the
>> > author and have a new document issued, but will such a change
>> > prevent advancement of the document on the standard track? If
>> > yes, is this really worth?
>> >
>> > Dan
>> >
>> >
>> > > -----Original Message-----
>> > > From: Wijnen, Bert (Bert) [mailto:bwijnen@lucent.com]
>> > > Sent: Wednesday, February 19, 2003 5:14 PM
>> > > To: bridge-mib@ietf.org
>> > > Subject: [Bridge-mib] VLAN-ID
>> > >
>> > >
>> > > Bridgemibbers....
>> > >
>> > > I do not see much (if any activity lately) :-(
>> > >
>> > > But I have a question.
>> > >
>> > > I see a VLAN ID represented in various forms:
>> > >
>> > > - draft-ietf-bridge-ext-v2-01.txt
>> > >     VlanId ::= TEXTUAL-CONVENTION
>> > >        STATUS      current
>> > >        DESCRIPTION "A 12-bit VLAN ID used in the VLAN Tag
header."
>> > >        SYNTAX      INTEGER (1..4094)
>> > > - somehwere I found:
>> > >     dot1vProtocolPortGroupVid OBJECT-TYPE
>> > >        SYNTAX      INTEGER (1..4094)
>> > >        MAX-ACCESS  read-create
>> > >        STATUS      current
>> > >        DESCRIPTION "The VID associated with a group of
protocols for
>> > >                     each port."
>> > >        REFERENCE   "IEEE 802.1v clause 8.4.4, 12.10.1.2"
>> > >
>> > > - In a DOCSIS document I find:
>> > >     docsQosPktClassVlanId OBJECT-TYPE
>> > >        SYNTAX          Integer32 (0..4095)
>> > >        MAX-ACCESS      read-only
>> > >        STATUS          current
>> > >
>> > > - In the framework PIB (draft-ietf-rap-frameworkpib-09.txt) I
find:
>> > >
>> > >   frwk802FilterVlanId OBJECT-TYPE
>> > >       SYNTAX         Integer32 (-1 | 1..4094)
>> > >       STATUS         current
>> > >       DESCRIPTION
>> > >           "The VLAN ID (VID) that uniquely identifies a VLAN
>> > >           within the device. This VLAN may be known or unknown
>> > >           (i.e., traffic associated with this VID has not yet
>> > >           been seen by the device) at the time this entry
>> > >           is instantiated.
>> > >
>> > >           Setting the frwk802FilterVlanId object to -1
>> > indicates that
>> > >           VLAN data should not be considered during traffic
>> > >           classification."
>> > >
>> > > - In rfc2613 I find:
>> > >    smonVlanIdStatsId OBJECT-TYPE
>> > >     SYNTAX     Integer32 (1..4094)
>> > >     MAX-ACCESS not-accessible
>> > >     STATUS     current
>> > >     DESCRIPTION
>> > >         "The unique identifier of the VLAN monitored for
>> > >          this specific statistics collection.
>> > >
>> > >         Tagged packets match the VID for the range between
>> > 1 and 4094.
>> > >         An external RMON probe MAY detect VID=0 on an Inter
Switch
>> > >         Link, in which case the packet belongs to a VLAN
>> > determined by
>> > >         the PVID of the ingress port. The VLAN to which
>> > such a packet
>> > >         belongs can be determined only by a RMON probe
>> > internal to the
>> > >         switch."
>> > >     REFERENCE
>> > >         "Draft Standard for Virtual Bridged Local Area
Networks,
>> > >           P802.1Q/D10, chapter 3.13"
>> > >
>> > > - In RFC2674 I find:
>> > >   VlanIndex ::= TEXTUAL-CONVENTION
>> > >     STATUS      current
>> > >     DESCRIPTION
>> > >         "A value used to index per-VLAN tables: values of 0 and
>> > >         4095 are not permitted; if the value is between 1 and
>> > >         4094 inclusive, it represents an IEEE 802.1Q VLAN-ID
with
>> > >         global scope within a given bridged domain (see VlanId
>> > >         textual convention).  If the value is greater than 4095
>> > >         then it represents a VLAN with scope local to the
>> > >         particular agent, i.e. one without a global VLAN-ID
>> > >         assigned to it. Such VLANs are outside the scope of
>> > >         IEEE 802.1Q but it is convenient to be able to manage
them
>> > >         in the same way using this MIB."
>> > >     SYNTAX      Unsigned32
>> > >
>> > > - IN RFC2674 I also find
>> > >    VlanId ::= TEXTUAL-CONVENTION
>> > >       STATUS      current
>> > >       DESCRIPTION
>> > >           "A 12-bit VLAN ID used in the VLAN Tag header."
>> > >       SYNTAX      INTEGER (1..4094)
>> > >
>> > > Not sure I found all occurances.
>> > >
>> > > So my question is: what is the CORRECT spec, and could we try
>> > > to define one (or a few)  TC(s) that everyone else can IMPORT
>> > > and use.
>> > >
>> > > Bert
>> > > _______________________________________________
>> > > Bridge-mib mailing list
>> > > Bridge-mib@ietf.org
>> > > https://www1.ietf.org/mailman/listinfo/bridge-mib
>> > >
>> >
>> _______________________________________________
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>> Bridge-mib@ietf.org
>> https://www1.ietf.org/mailman/listinfo/bridge-mib
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