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

From: [email-masked]
Date: Wed, 09 Feb 2011 12:00:02 -0800

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/

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Internet-Draft.

---

From: Xu Xiaohu <[email-masked]>
Date: Mon, 28 Feb 2011 10:59:37 +0800

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: [email-masked] [mailto:[email-masked]] 代表
> [email-masked]
> 发送时间: 2011年2月10日 4:00
> 收件人: [email-masked]
> 抄送: [email-masked]
> 主题: [Isis-wg] I-D Action:draft-ietf-isis-layer2-11.txt
> 
> This draft is a work item of the IS-IS for IP Internets Working Group of
the
> IETF.

---

From: Stewart Bryant <[email-masked]>
Date: Mon, 28 Feb 2011 11:53:02 +0000

Xiaohu

This is something that should have been proposed months ago.

The document is in the RFC editor's queue, and this change would require
it to go back to the working group, something which I would not be
prepared to do unless that is the consensus of both working groups
affected.

Stewart

On 28/02/2011 02:59, Xu Xiaohu wrote:
> _______________________________________________
> Isis-wg mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/isis-wg

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---

From: Donald Eastlake <[email-masked]>
Date: Mon, 28 Feb 2011 07:01:24 -0500

Hi,

There has been discussion of "breaking the 4,096 limit" in the TRILL
WG, as you can see from the mailing list archives. Most, possible all,
the suggested solutions do not require any change in the size of a
"VLAN ID" but add other identifiers or use other techniques.

Thanks,
Donald

PS: I am about to leave on a trip and will probably be unable to
respond further until I arrive at my destination.
=============================
 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 155 Beaver Street
 Milford, MA 01757 USA
 [email-masked]

---

From: "Bragg, Nigel" <[email-masked]>
Date: Mon, 28 Feb 2011 08:55:01 -0500

Hello,

IS-IS for SPBM distributes and uses a 24-bit I-SID as the
end-point identifier for a virtual LAN segment :
-   VLAN space is not an issue.

Nigel

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Donald Eastlake
Sent: 28 February 2011 12:01
To: Xu Xiaohu
Cc: [email-masked]; [email-masked]
Subject: Re: [Isis-wg] I-D Action:draft-ietf-isis-layer2-11.txt

Hi,

Thanks,
Donald

---

From: Vishwas Manral <[email-masked]>
Date: Mon, 28 Feb 2011 07:26:08 -0800

Hi Xu,

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.

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.

Thanks,
Vishwas

---

From: Peter Ashwood-Smith <[email-masked]>
Date: Mon, 28 Feb 2011 11:19:43 -0500

Vishwas, couple of points below.

> 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.

>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.

Cheers,

Peter

---

From: Vishwas Manral <[email-masked]>
Date: Mon, 28 Feb 2011 09:35:11 -0800

Hi Peter/ Xu,

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

> 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 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