Re: [Isis-wg] I-D Action:draft-ietf-isis-layer2-11.txt

[Vishwas Manral <[e-mail]>]

Hi Peter/ Xu,

TRILL allows the detection of VLAN translation already and will work
correctly with the way things currently are.

>> In the way TRILL works (or SPB), they encapsulate the inner Ethernet
>> packet and transport it across the domain. The domain itself uses just
>> one VLAN (Designated VLAN) for forwarding, except at the edge.
>
> SPB uses up to 16 backbone VLANs not just one. They are used to provide
> diversity of routing and also tennant routing isolation in the core network.
> I.e. tenant A and B do not share a given link or node. Infact more than 16
> could be used where the first 16 belong to Multi Topology #1 and an
> additional set belong to a different Multi Topology.
I agree. Sorry for being unclear the first part is what I meant is for
SPB too. The designated VLAN concept is in TRILL and probably what you
stated about SPB is true for SPB.

>>To map services to SPB uses I-SID (which is different from the outer
>>VLAN) - see 802.1ah. TRILL also has a plan to optionally add such a
>>field in the packet. As this is end to end, it may not affect
>>forwarding on the intermediate devices. If this has to be transported
>>in the IS-IS, we may require a TLV you have mentioned.
>
> It is only true that an ISID does not affect core devices if you do not wish
> to scope multicast to just members of that ISID or if you wish not to do
> multicast and instead do serial unicast. Usually however we want to scope
> the multicast and wish to do tandem replication in which case the ISID has
> to be considered in the construction of the state for tandem multicast.
OK. Let me read how you are doing Multicast in SPB and using the I-SID.

Thanks,
Vishwas

> Cheers,
>
> Peter
>
> 2011/2/27 Xu Xiaohu <[e-mail]>:
>> Hi all,
>>
>> As I heard from some could data center operators, 4096 VLANs would not be
>> enough for isolating the huge amount of tenants in their future data
> center
>> networks. Besides, the VLAN translation is a desirable feature in some
>> scenarios (e.g., the same VLAN ID in different parts of the data center
>> network is used for different tenants while different VLAN IDs in
> different
>> parts of the data center network are used to connect a single tenant).
>>
>> Hence, I wonder whether it is possible to replace the fixed-length VLAN ID
>> field (e.g., the VLAN-ID field in the MAC-reachability TLV as shown below)
>> with a tenant/VPN instance ID TLV. With such TLV, at least the two
> problems
>> mentioned above can be solved easily.
>>
>> Best wishes,
>> Xiaohu
>>
>> ========================================================================
>> 2.1.  The MAC-Reachability TLV
>>
>>   The MAC-Reachability (MAC-RI) TLV is IS-IS TLV type 141 and has the
>>   following format:
>>
>>   +-+-+-+-+-+-+-+-+
>>   | Type= MAC-RI  |                  (1 byte)
>>   +-+-+-+-+-+-+-+-+
>>   |   Length      |                  (1 byte)
>>   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>   |   Topology-Id/ Nickname       |  (2 bytes)
>>   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>   |   Confidence  |                  (1 byte)
>>   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>   |  RESV |      VLAN-ID          |  (2 bytes)
>>   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>   |                          MAC (1)    (6 bytes)                 |
>>   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>   |                   .................                           |
>>   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>   |                          MAC (N)    (6 bytes)                 |
>>   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>
>>
>>
>>> -----邮件原件-----
>>> 发件人: [e-mail] [mailto:[e-mail]] 代表
>>> [e-mail]
>>> 发送时间: 2011年2月10日 4:00
>>> 收件人: [e-mail]
>>> 抄送: [e-mail]
>>> 主题: [Isis-wg] I-D Action:draft-ietf-isis-layer2-11.txt
>>>
>>> A New Internet-Draft is available from the on-line Internet-Drafts
>>> directories.
>>> This draft is a work item of the IS-IS for IP Internets Working Group of
>> the
>>> IETF.
>>>
>>>
>>>       Title           : Extensions to IS-IS for Layer-2 Systems
>>>       Author(s)       : A. Banerjee, D. Ward
>>>       Filename        : draft-ietf-isis-layer2-11.txt
>>>       Pages           : 11
>>>       Date            : 2011-02-09
>>>
>>> This document specifies the Intermediate System to Intermediate
>>> System (IS-IS) extensions necessary to support link state routing for
>>> any protocols running directly over Layer-2.  While supporting this
>>> concept involves several pieces, this document only describes
>>> extensions to IS-IS.  Furthermore, the Type, Length, Value pairs
>>> (TLVs) described in this document are generic Layer-2 additions and
>>> specific ones as needed are defined in the IS-IS technology specific
>>> extensions.  We leave it to the systems using these IS-IS extensions
>>> to explain how the information carried in IS-IS is used.
>>>
>>> A URL for this Internet-Draft is:
>>> http://www.ietf.org/internet-drafts/draft-ietf-isis-layer2-11.txt
>>>
>>> Internet-Drafts are also available by anonymous FTP at:
>>> ftp://ftp.ietf.org/internet-drafts/
>>>
>>> Below is the data which will enable a MIME compliant mail reader
>>> implementation to automatically retrieve the ASCII version of the
>>> Internet-Draft.
>>
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