TRILL (Transparent Interconnection of Lots of Links): ESADI (End Station Address Distribution Information) Protocol
draft-ietf-trill-esadi-04
The information below is for an old version of the document.
| Document | Type | Active Internet-Draft (trill WG) | |
|---|---|---|---|
| Authors | Hongjun Zhai , fangwei hu , Radia Perlman , Donald E. Eastlake 3rd , Olen Stokes | ||
| Last updated | 2013-11-26 | ||
| Replaces | draft-hu-trill-rbridge-esadi | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Formats | plain text htmlized pdfized bibtex | ||
| Reviews |
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| Stream | WG state | WG Consensus: Waiting for Write-Up | |
| Document shepherd | Erik Nordmark | ||
| Shepherd write-up | Show Last changed 2013-11-15 | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
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| Send notices to | (None) |
draft-ietf-trill-esadi-04
TRILL Working Group Hongjun Zhai
INTERNET-DRAFT Fangwei Hu
Intended status: Proposed Standard ZTE
Updates: 6325 Radia Perlman
Intel Labs
Donald Eastlake
Huawei
Olen Stokes
Extreme Networks
Expires: May 25, 2014 November 26, 2013
TRILL (Transparent Interconnection of Lots of Links):
ESADI (End Station Address Distribution Information) Protocol
<draft-ietf-trill-esadi-04.txt>
Abstract
The IETF TRILL (Transparent Interconnection of Lots of Links)
protocol provides least cost pair-wise data forwarding without
configuration in multi-hop networks with arbitrary topologies and
link technologies. TRILL supports multi-pathing of both unicast and
multicast traffic. Devices that implement the TRILL protocol are
called TRILL Switches or RBridges (Routing Bridges).
ESADI (End Station Address Distribution Information) is an optional
protocol by which a TRILL switch can communicate, in a Data Label
(VLAN or Fine Grained Label) scoped way, end station addresses and
other information to TRILL switches participating in ESADI for the
relevant Data Label. This document updates RFC 6325, specifically
the documentation of the ESADI protocol, and is not backwards
compatible.
Status of This Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
Distribution of this document is unlimited. Comments should be sent
to the TRILL working group mailing list: <trill@ietf.org>.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
H. Zhai, et al [Page 1]
INTERNET-DRAFT TRILL: ESADI
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft
Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
H. Zhai, et al [Page 2]
INTERNET-DRAFT TRILL: ESADI
Table of Contents
1. Introduction............................................4
1.1 Content and Precedence.................................5
1.2 Terminology............................................5
2. ESADI Protocol Overview.................................7
2.1 ESADI Virtual Link.....................................9
2.2 ESADI Neighbor Determination..........................10
2.3 ESADI Payloads........................................10
3. ESADI DRB Determination................................12
4. ESADI PDU processing...................................13
4.1 Unicasting ESADI PDUs.................................13
4.2 General Transmission of ESADI PDUs....................14
4.3 General Receipt of ESADI PDUs.........................14
4.4 Details of Receiving and Sending ESADI PDUs...........15
4.4.1 ESADI-CSNP Receipt..................................15
4.4.2 ESADI-PSNP Receipt..................................16
4.4.3 ESADI-LSP Receipt...................................16
4.4.4 Passage of Time.....................................16
4.4.5 Neighbor Appearance.................................16
5. End Station Addresses..................................18
5.1 Learning Confidence Level.............................18
5.2 Forgetting End Station Addresses......................18
5.3 Duplicate MAC Address.................................18
6. ESADI-LSP Contents.....................................21
6.1 ESADI Parameter Data..................................21
6.2 MAC Reachability TLV..................................22
6.3 Default Authentication................................23
7. IANA Considerations....................................24
7.1 ESADI Participation and Capability Flags..............24
7.2 TRILL GENINFO TLV.....................................25
8. Security Considerations................................27
9. Acknowledgements.......................................27
Normative references......................................28
Informative References....................................29
Appendix A: Changes to [RFC6325]..........................30
Appendix Z: Change History................................31
Authors' Addresses........................................33
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1. Introduction
The IETF TRILL (Transparent Interconnection of Lots of Links)
protocol [RFC6325] provides least cost pair-wise data forwarding
without configuration in multi-hop networks with arbitrary topologies
and link technologies, safe forwarding even during periods of
temporary loops, and support for multi-pathing of both unicast and
multicast traffic. TRILL accomplishes this with the IS-IS
(Intermediate System to Intermediate System) [IS-IS] [RFC1195]
[rfc6326bis] link-state routing protocol using a header with a hop
count. The design supports optimization of the distribution of
multi-destination frames and two types of data labeling: VLANs
(Virtual Local Area Networks [RFC6325]) and FGLs (Fine Grained
Labels, [RFCfgl]). Devices that implement TRILL are called TRILL
switches or RBridges (Routing Bridges).
There are five ways a TRILL switch can learn end station addresses,
as described in Section 4.8 of [RFC6325]. The ESADI (End Station
Address Distribution Information) protocol is an optional Data Label
scoped way TRILL switches can communicate, with each other,
information such as end station addresses and their TRILL switch of
attachment. A TRILL switch that is announcing interest in a Data
Label MAY use the ESADI protocol to announce the end station address
of some or all of its attached end stations in that Data Label to
other TRILL switches that are running ESADI for that Data Label. (In
the future, ESADI may also be used for additional types of
information.)
By default, TRILL switches with connected end stations learn
addresses from the data plane when ingressing and egressing native
frames although such learning can be disabled. The ESADI protocol's
potential advantages over data plane learning include the following:
1. Security advantages: (1a) The ESADI protocol can be used to
announce end stations with an authenticated enrollment (for
example enrollment authenticated by cryptographically based EAP
(Extensible Authentication Protocol [RFC3748]) methods via
[802.1X]). (1b) The ESADI protocol supports cryptographic
authentication of its message payloads for more secure
transmission.
2. Fast update advantages: The ESADI protocol provides a fast update
of end station MAC (Media Access Control) addresses and their
TRILL switch of attachment. If an end station is unplugged from
one TRILL switch and plugged into another, frames ingressed for
that end station's MAC address can be black holed. That is, they
can be sent just to the older egress TRILL switch that the end
station was connected to until cached address information at some
remote ingress TRILL switch times out, possibly for tens of
seconds [RFC6325].
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MAC address reachability information, some ESADI parameters, and
optionally authentication information are carried in ESADI packets
rather than in the TRILL IS-IS protocol. As specified below, ESADI
is, for each Data Label, a virtual logical topology overlay in the
TRILL topology. An advantage of using ESADI over using TRILL IS-IS is
that the end station attachment information is not flooded to all
TRILL switches but only to TRILL switches advertising ESADI
participation for the Data Label in which those end stations occur.
1.1 Content and Precedence
This document updates [RFC6325], the TRILL base specification,
essentially replacing the description of the ESADI protocol,
providing more detail, and prevailing over [RFC6325] where they
conflict. The changes are summarized in Appendix A. These changes are
not backwards compatible because, among other things, they change the
format of ESADI-LSPs.
Section 2 of this document is the ESADI protocol overview. Section 3
specifies ESADI DRB determination. Section 4 discusses the
processing of ESADI PDUs. Section 5 discusses interaction with other
modes of end station address learning. And Section 6 describes the
ESADI-LSP and its contents.
1.2 Terminology
This document uses the acronyms defined in [RFC6325] and the
following:
Data Label - VLAN or FGL.
FGL - Fine Grained Label [RFCfgl].
LSP - Link State PDU.
LSP number zero - A Link State PDU with fragment number equal to
zero.
PDU - Procotol Data Unit.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. Capitalized
IANA Considertions terms such as "IETF Review" as to be interpreted
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as described in [RFC5226].
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2. ESADI Protocol Overview
ESADI is a Data Label scoped way for TRILL switches (also known as
RBridges) to announce and learn end station addresses rapidly and
securely. An RBridge that is announcing participation in ESADI for
one or more Data Labels is called an ESADI RBridge.
ESADI is a separate optional protocol from the mandatory TRILL IS-IS
implemented by all RBridges in a campus. There is a separate ESADI
instance for each Data Label (VLAN or FGL). In essence, for each Data
Label, there is a modified instance of the IS-IS reliable flooding
mechanism in which ESADI RBridges may choose to participate. (These
are not the instances specified in [RFC6822].) It is an
implementation decision how independent the multiple ESADI instances
at an RBridge are. For example, the ESADI link state database could
be in a single database with a field in each record indicating the
Data Label to which it applies or could be a separate database per
Data Label. But the update process operates separately for each ESADI
instance and independently from the TRILL IS-IS update process.
ESADI does no routing so there is no reason for pseudo-nodes in ESADI
and none are created. Furthermore, there may be a requirement for a
relatively large amount of data to be distributed through ESADI which
might take a large number of ESADI-LSP fragments. ESADI-LSP, ESADI-
CSNP, and ESADI-PSNP payloads are therefore formated as Extended
Level 1 Circuit Scope PDUs [FS-LSP] (see also Section 6). This allows
up to 2**16 fragments but does not support link state data associated
with pseudo-nodes.
After the TRILL header, ESADI packets have an inner Ethernet header
with the Inner.MacDA of "All-Egress-RBridges" (formerly called "All-
ESADI-RBridges"), an inner Data Label specifying the VLAN or FGL of
interest, and the "L2-IS-IS" Ethertype followed by the ESADI payload
as shown in Figure 1.
+--------------------------------+
| Link Header |
+--------------------------------+
| TRILL Data Header |
+--------------------------------+
| Inner Ethernet Addresses |
+--------------------------------+
| Data Label |
+--------------------------------+
| ESADI Payload |
+--------------------------------+
| Link Trailer |
+--------------------------------+
Figure 1. TRILL ESADI Packet Overview
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TRILL ESADI packets sent on an Ethernet link are structured as shown
below. The outer VLAN tag will not be present if it was stripped by
an Ethernet port out of which the packet was sent.
Outer Ethernet Header:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Hop Destination Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Hop Destination Addr. | Sending RBridge Port MAC Addr.|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sending RBridge Port MAC Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
...Ethernet frame tagging including optional Outer.VLAN tag...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ethertype = TRILL 0x22F3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
TRILL Header: +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| V | R |M|Op-Length| Hop Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Egress Nickname | Ingress (Origin) Nickname |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Inner Ethernet Header:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| All-Egress-RBridges |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| All-Egress-RBridges cont. | Origin RBridge MAC Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Origin RBridge MAC Address continued |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| VLAN or FGL Data Label (4 or 8 bytes) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ethertype = L2-IS-IS 0x22F4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
ESADI Payload (formatted as IS-IS):
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IS-IS Common Header, IS-IS PDU Specific Fields, IS-IS TLVs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Frame Check Sequence:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FCS (Frame Check Sequence) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: ESADI Ethernet Link Packet Format
The Next Hop Destination Address or Outer.MacDA is the All-RBridges
multicast address if the ESADI PDU is being multicast. If it is being
unicast, the Next Hop Destination Address is the unicast address of
the next hop RBridge. The VLAN for the Outer.VLAN information, if
present, will be the Designated VLAN for the link on which the packet
is sent. The V and R fields will be zero while the M field will be
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INTERNET-DRAFT TRILL: ESADI
one unless the ESADI PDU was unicast, in which case the M field will
be zero. The Data Label specified will be the VLAN or FGL to which
the ESADI packet applies. The Origin RBridge MAC Address or
Inner.MacSA MUST be a MAC address unique across the campus owned by
the RBridge originating the ESADI packet, for example, any of its
port MAC addresses if it has any Ethernet ports, and each RBridge
MUST use the same Inner.MacSA for all of the ESADI packets that
RBridge originates.
TRILL ESADI packets sent on a PPP link are structured as shown below
[RFC6361].
PPP Header:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PPP = TNP (TRILL data) 0x005D |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
TRILL Header: +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| V | R |M|Op-Length| Hop Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Egress Nickname | Ingress (Origin) Nickname |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Inner Ethernet Header:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| All-Egress-RBridges |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| All-Egress-RBridges cont. | Origin RBridge MAC Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Origin RBridge MAC Address continued |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| VLAN or FGL Data Label (4 or 8 bytes) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ethertype = L2-IS-IS 0x22F4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
ESADI Payload (formatted as IS-IS):
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IS-IS Common Header, IS-IS PDU Specific Fields, IS-IS TLVs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
PPP Check Sequence:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PPP Check Sequence |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: ESADI PPP Link Packet Format
2.1 ESADI Virtual Link
All transit RBridges forward ESADI packets as if they were ordinary
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TRILL Data packets. Because of this forwarding, it appears to an
instance of the ESADI protocol at an RBridge that it is directly
connected by a multi-access virtual link to all RBridges in the
campus that are data reachable from it (see Section 2 of
[ClearCorrect]) and are running ESADI for that Data Label. No
"routing" computation or routing decisions ever have to be performed
by ESADI. An ESADI RBridge merely transmits the ESADI packets it
originates on this virtual link as described for TRILL Data packets
in [RFC6325] and [RFCfgl]. For multicast ESADI packets it may use any
distribution tree that it might use for an ordinary multi-destination
TRILL Data packet. RBridges that do not implement the ESADI protocol,
do not have it enabled, or are not participating for the Data Label
of an ESADI packet do not decapsulate or locally process the TRILL
ESADI packet. Thus, ESADI packets are transparently tunneled through
transit RBridges.
2.2 ESADI Neighbor Determination
The ESADI instance for Data Label X at an RBridge RB1 determines who
its adjacent ESADI neighbors are by examining the TRILL IS-IS link
state database for RBridges that are data reachable from RB1 (see
Section 2 of [ClearCorrect]) and are announcing their participation
in Data Label X ESADI. When an RBridge RB2 becomes data unreachable
from RB1 or the relevant entries for RB2 are purged from the core IS-
IS link state database, it is lost as a neighbor and also dropped
from any ESADI instances, and when RB2 is no longer announcing
participation in Data Label X ESADI, it ceases to be a neighbor for
the Data Label X ESADI instance. All these considerations being Data
Label scoped. Because of these mechanisms, there are no "Hellos" sent
in ESADI.
Participation announcement in a VLAN scoped ESADI instance is through
setting a flag bit in the Interested VLANs sub-TLV and announcement
for an FGL scoped ESADI instance is through setting a flag bit in the
Interested Labels sub-TLV [rfc6326bis]. (See Section 7.1)
2.3 ESADI Payloads
TRILL ESADI packet payloads are structured like IS-IS Extended Level
1 Circuit Scoped LSP, CSNP, and PSNP PDUs [FS-LSP], except as
indicated below, but are always TRILL encapsulated on the wire as if
they were TRILL Data packets. The information distributed by the
ESADI protocol includes a list of local end station MAC addresses
connected to the originating RBridge and, for each such address, a
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one octet unsigned "confidence" rating in the range 0-254 (see
Section 6.2). It is entirely up to the originating RBridge which
locally connected MAC addresses it wishes to advertise via ESADI and
with what confidence. It MAY advertise all, some, or none of such
addresses. In addition, some ESADI parameters of the advertising
RBridge (see Section 6.1) and optionally authentication information
(see Section 6.3) are included. Future uses of ESADI may distribute
other types of information.
TRILL ESADI-LSPs MUST NOT contain a Data Label ID in their payload.
The Data Label to which the ESADI data applies is the Data Label of
the TRILL Data packet enclosing the ESADI payload. If a Data Label ID
could occur within the payload, it might conflict with that TRILL
Data packet Data Label and could conflict with any future Data Label
mapping scheme that may be adopted [VLANmapping]. If a VLAN or FGL ID
field within an ESADI-LSP PDU does include a value, that field's
contents is ignored.
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3. ESADI DRB Determination
Because ESADI does no adjacency announcement or routing, the ESADI-
DRB never creates a pseudonode. But a DRB (Designated RBridge
[rfc6327bis]) is still needed for ESADI-LSP synchronization by
issuing ESADI-CSNP PDUs and responding to ESADI-PSNP PDUs.
Generally speaking, the DRB election on the ESADI virtual link (see
Section 2.1) operates similarly to a TRILL IS-IS broadcast link
[rfc6327bis] with the following exceptions: In the Data Label X
ESADI-DRB election at RB1 on an ESADI virtual link, the candidates
are the local ESADI instance for Data Label X and all remote ESADI
instances at RBridges that (1) are data reachable from RB1
[ClearCorrect], and (2) are announcing in their TRILL IS-IS LSP that
they are participating in ESADI for Data Label X. The winner is the
instance with the highest ESADI Parameter 7-bit priority field with
ties broken by System ID, comparing fields as unsigned integers with
the larger magnitude considered higher priority. "SNPA/MAC address"
is not considered in this tie breaking and there is no "Port ID".
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4. ESADI PDU processing
Data Label X ESADI neighbors are usually not connected directly by a
physical link, but are always logically connected by a virtual link
(see Section 2.1). There could be hundreds or thousands of ESADI
RBridges (TRILL switches) on the virtual link. There are only ESADI-
LSP, ESADI-CSNP and ESADI-PSNP PDUs used in ESADI. In particular,
there are no Hello or MTU PDUs because ESADI does not build a
topology, does not do any routing, and uses the campus Sz MTU.
4.1 Unicasting ESADI PDUs
In IS-IS, PDU multicasting is normal on a local link and no effort is
made to optimize to unicast because on the typical physical link for
which IS-IS was designed (commonly a piece of multi-access Ethernet
cable) any frame made the link busy for that frame time. But to ESADI
instances, what appears to be a simple multi-access link is generally
a set of multi-hop distribution trees that may or may not be pruned.
Thus, transmitting a multicast frame on such a tree can impose a
substantially greater load than transmitting a unicast frame. This
load may be justified if there are likely to be multiple listeners
but may not be justified if there is only one recipient of interest.
For this reason, under some circumstances, ESADI-LSP and ESADI-PSNP
PDUs MAY be TRILL unicast if it is confirmed that the destination
RBridge supports receiving unicast ESADI PDUs (see Section 6.1).
To support unicasting of ESADI PDUs, Section 4.6.2.2 of [RFC6325] is
replaced with the following:
"4.6.2.2. TRILL ESADI Packets
If M=1, the egress nickname designates the distribution tree. The
packet is forwarded as described in Section 4.6.2.5. In addition,
if the forwarding RBridge is (1) interested in the specified VLAN
or Fine Grained Label, (2) implements the TRILL ESADI protocol,
and (3) ESADI is enabled for that VLAN or Fine Grained Label, the
inner frame is decapsulated and provided to that local ESADI
protocol.
If M=0 and the egress nickname is not that of the receiving
RBridge, the packet is forwarded as for known unicast TRILL Data
in Section 4.6.2.4. If M=0 and the egress nickname is that of the
receiving RBridge and the receiving RBridge supports unicast ESADI
PDUs, then the ESADI packet is decapsulated and processed if it
meets the three numbered conditions in the paragraph above,
otherwise it is discarded."
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The references to "4.6.2.2", "4.6.2.4", and "4.6.2.5" above refer to
those sections in [RFC6325].
4.2 General Transmission of ESADI PDUs
An ESADI instance SHOULD NOT transmit any ESADI PDUs if it has no
ESADI neighbors. They would just be a waste of bandwidth.
The MTU available to ESADI payloads is at least 24 bytes less than
that available to TRILL IS-IS because of the additional fields
required ( 2(TRILL Ethertype) + 6(TRILL Header) + 6(Inner.MacDA) +
6(Inner.MacSA) + 4/8(Inner.VLAN/Inner.FGL) bytes). Thus the inner
ESADI payload, starting with the Intradomain Routeing Protocol
Discriminator byte, MUST NOT exceed Sz minus 24 for a VLAN ESADI
instance or Sz minus 28 for an FGL ESDAI instance; however, if a
larger payload is received, it is processed normally. (See [RFC6325]
and [ClearCorrect] for discussions of Sz and MTU.)
The format of a unicast ESADI packet is the format of multicast TRILL
ESADI packet, in Section 2 above, except as follows:
o On an Ethernet link, in the Outer Ethernet Header the Outer.MacDA
is the unicast address of the next hop RBridge.
o In the TRILL header, the M bit is set to zero and the Egress
Nickname is the nickname of the destination RBridge.
In all cases where this document says that an ESADI PDU is multicast,
if the transmitting RBridge has only one neighbor and that neighbor
advertises support for unicast, the PDU MAY be unicast.
[FS-LSP] provides a priority bit to indicate that an LSP fragment
should be flooded with high priority. This bit SHOULD be set on
ESADI-LSP fragment zero and SHOULD NOT be set on any other ESADI-LSP
fragment.
4.3 General Receipt of ESADI PDUs
Because ESADI neighbor adjacency is in terms of System ID, all PDU
acceptance tests that in TRILL/IS-IS check that the PDU is from an
adjacent router instead check that the System ID is that of an ESADI
neighbor and do not check either the source Inner or Outer SNPA/MAC.
If an ESADI instance believes that it has no ESADI neighbors, it
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ignores any ESADI PDUs it receives.
4.4 Details of Receiving and Sending ESADI PDUs
Event | Section
--------------+-------------------
Receive | See
ESADI-CSNP | Section 4.4.1
--------------+-------------------
Receive | See
ESADI-PSNP | Section 4.4.2
--------------+-------------------
Receive | See
ESADI-LSP | Section 4.4.3
--------------+-------------------
Passage | See
of Time | Section 4.4.4
--------------+-------------------
Neighbor | See
Appearance | Section 4.4.5
--------------+-------------------
4.4.1 ESADI-CSNP Receipt
If an ESADI RBridge RB1 believes it is DRB on a virtual link for Data
Label X, it ignores an ESADI-CSNP it receives.
If RB1 believes it is not DRB:
When RB1 receives an ESADI-CSNP from RB2 and detects that it has
ESADI-LSPs that RB2 is missing, it sets the transmission flag only
for its own ESADI-LSPs that RB2 is missing. Missing ESADI-LSPs
originated by other ESADI RBridges will be detected by those other
ESADI RBridges because all data reachable ESADI RBridges
participating for Data Label X are adjacent.
When RB1 receives an ESADI-CSNP from RB2 and detects that it is
missing ESADI-LSPs originated by RBridges reachable from RB1 that
RB2 has, it generates one or more ESADI-PSNP PDUs. Generally,
ESADI-PSNPs are multicast and may be fragmented as in IS-IS;
however, if RB1 is missing ESADI-LSPs from RBx and RBx is
advertising unicast ESADI PDU support, RB1 MAY construct one or
more EASDI-PSNP fragments listing only RBx ESADP-LSPs and unicast
those ESADI-PSNPs to RBx.
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4.4.2 ESADI-PSNP Receipt
When RBx receives an ESADI-PSNP PDU, if RBx is the originator of any
ESADI-LSPs requested by the ESADI-PSNP those ESADI-LSPs will be
multicast on the virtual link.
4.4.3 ESADI-LSP Receipt
Processing of a received ESADI-LSP is as in [FS-LSP].
In the case of receiving an ESADI-LSP with a smaller sequence number
than the copy stored in the local EASDI Link State Database the local
ESADI instance will also schedule multicasting its stored copy.
4.4.4 Passage of Time
If an ESADI instance believes it is DRB, it multicasts an ESADI-CSNP
periodically (thrice per CSNP Time, see Section 6.1) to keep the link
state database synchronized among its neighbors on the virtual link.
The multi-hop TRILL multi-destination packet distribution with
Reverse Path Forwarding Check will typically be less reliable than
the single hop link-local LSP synchronization of TRILL IS-IS.
Therefore, for LSP synchronization robustness, in addition to sending
ESADI-CSNPs when it is DRB, an ESADI RBridge SHOULD also transmit an
ESADI-CSNP for an ESADI instance if all of the following conditions
are met:
o it sees one or more ESADI neighbors for that instance, and
o it does not believe it is DRB for the ESADI instance, and
o it has not received or sent an ESADI-CSNP PDU for the instance for
the CSNP Time (see Section 6.1) of the DRB.
4.4.5 Neighbor Appearance
When an ESADI instance sees that it has a new neighbor, its self-
originated EASDI-LSP fragments are scheduled to be sent and MAY be
unicast to that neighbor if the neighbor is announcing in its LSP
that it supports unicast ESADI (see Section 6.1). If all the other
ESADI instances for the same Data Label send their self-originated
ESADI-LSPs immediately, there may be a surge of traffic to that new
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INTERNET-DRAFT TRILL: ESADI
neighbor. So the ESADI instances SHOULD wait an interval of time
before sending their ESADI-LSP to a new neighbor. The interval time
value is up to the device implementation and is subject to the usual
IS-IS timing jitter. One suggestion is that the interval time can be
assigned a random value with a range based on the RBridge's nickname
(or any one of its nicknames if it holds more than one) such as ( 2 *
nickname / 0xFFC0 ) seconds assuming "nickname" and 0xFFCO to be
unsigned quantities.
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5. End Station Addresses
The subsections below discuss end station address considerations in
the context of ESADI.
5.1 Learning Confidence Level
The confidence level mechanism allows an RBridge campus manager to
cause certain address learning sources to prevail over others. MAC
address information learned through a registration protocol, such as
[802.1X] with a cryptographically based EAP [RFC3748] method, might
be considered more reliable than information learned through the mere
observation of data traffic. When such authenticated learned address
information is transmitted via the ESADI protocol, the use of
authentication in the TRILL ESADI-LSP packets could make tampering
with it in transit very difficult. As a result, it might be
reasonable to announce such authenticated information via the ESADI
protocol with a high confidence, so it would be used in preference to
any alternative learning from data observation.
5.2 Forgetting End Station Addresses
The end station addresses learned through the TRILL ESADI protocol
should be forgotten through changes in ESADI-LSPs. The time out of
the learned end station address is up to the originating RBridge that
decides when to remove such information from its ESADI-LSPs (or up to
ESADI protocol timeouts if the originating RBridge becomes
unreachable).
If RBridge RBn participating in the TRILL ESADI protocol for Data
Label X no longer wishes to participate in ESADI, it ceases to
participate by (1) clearing the ESADI participation bit in the
appropriate Interested VLANs or Interested Labels sub-TLV and (2)
sending a final ESADI-LSP nulling out its ESADI-LSP information.
5.3 Duplicate MAC Address
With ESADI, it is possible to persistently see occurrences of the
same MAC address with the same Data Label being advertised as
reachable by two or more RBridges. The specification of how to handle
this situation in [RFC6325] is updated by replacing the last sentence
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INTERNET-DRAFT TRILL: ESADI
of the last paragraph of Section 4.2 of [RFC6325] as shown below to
provide better traffic spreading while avoiding possible address
flip-flopping.
As background, assume some end station or set of end stations have
two or more ports with the same MAC&label with each port connected to
different RBridges (RB1, RB2, ...) by separate links. (Label is a
VLAN or FGL.) With ESADI, some other RBridge, RB0, can persistently
see that MAC&label connected to multiple RBridges. When RB0 ingresses
a frame destined for that MAC&label, the current [RFC6325] text
permits a wide range of behavior. In particular, it would permit RB0
to use some rule such as always send to the egress with the lowest
System ID, which would put all of this traffic through one of the
egress RBridges and one of the end station ports. There would be no
load spreading even if there were multiple different ingress RBridges
and/or different MAC addresses with the same reachability. It also
would also permit RB0 to send different traffic to different egresses
by doing ECMP at a flow level, which would likely result in return
traffic to RB0 from RB1, RB2, ... for the same MAC&label. The
resulting address flip-flopping could cause problems. This update to
[RFC6325] avoids these potential difficulties by requiring RB0 to use
one of the following two policies: (1) use only one egress for a
particular MAC&label but to select that egress pseudo-randomly based
on the topology including MAC reachability or (2) if it will not be
disturbed by the returning TRILL Data packets showing the same
MAC&label flip-flopping between different ingresses, it may use ECMP.
Assuming multiple ingress RBridges and/or multiple MAC addresses,
strategy 1 should result in load spreading without address flip-
flopping while strategy 2 will produce more uniform load spreading
with address flip-flopping from the point of view of RB0.
OLD [RFC6325] text:
"... If confidences are also tied between the duplicates, for
consistency it is suggested that RB2 direct all such frames (or
all such frames in the same ECMP flow) toward the same egress
RBridge; however, the use of other policies will not cause a
network problem since transit RBridges do not examine the
Inner.MacDA for known unicast frames."
NEW [RFC6325] text:
"...
If confidences are also tied between the duplicates then RB2 MUST
adopt one of the following two strategies:
1. In a pseudo-random way [RFC4086], select one of the egress
RBridges that is least cost from RB2 and to which the
destination MAC appears to be attached and send all traffic for
the destination MAC and VLAN (or FGL) to that egress. This
pseudo-random choice need only be changed when there is a
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change in campus topology or MAC attachment information. Such
pseudo-random selection will, over a population of ingress
RBridges, probabilistically spread traffic over the possible
egress RBridges. Reasonable inputs to the pseudo-random
selection are the ingress RBridge System ID and/or nickname,
the VLAN or FGL, the destination MAC address, and a vector of
the RBridges with connectivity to that MAC and VLAN. There is
no need for different RBridges to use the same pseudo-random
function.
2. If RB2 supports ECMP and will not be disturbed by return
traffic from the same MAC and VLAN (or FGL) coming from
different ingress RBridges, then it MAY send traffic using ECMP
at the flow level to the egress RBridges that are least cost
from RB2 and to which the destination MAC appears to be
attached."
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6. ESADI-LSP Contents
The only PDUs used in ESADI are the ESADI-LSP, ESADI-CSNP, and ESADI-
PSNP PDUs. Currently, the contents of an ESADI-LSP consists of zero
or more MAC Reachability TLVs, optionally an Authentication TLV, and
exactly one ESADI parameter APPsub-TLV. Other data may be included in
the future and, as in IS-IS, an ESADI instance ignores any TLVs or
sub-TLVs it does not understand. Because these PDUs are formatted as
Extended Level 1 Circuit Scope PDUs [FS-LSP], the Type and Length
fields in the TLVs are 16-bit.
This section specifies the format for the ESADI parameter data
APPsub-TLV, gives the reference for the ESADI MAC Reachability TLV,
and discusses default authentication configuration.
For robustness, the payload for an ESADI-LSP number zero and any
ESADI-CSNP or ESADI-PSNP covering fragment zero MUST NOT exceed 1470
minus 24 bytes in length (1446 bytes) if it has an Inner.VLAN or 1470
minus 28 bytes (1442 bytes) if it has an Inner.FGL. But if an ESADI-
LSP number zero or such an ESADI-CSNP or ESADI-PSNP is received that
is longer, it is still processed normally.
6.1 ESADI Parameter Data
The figure below presents the format of the ESADI parameter data.
This APPsub-TLV MUST be included in a TRILL GENINFO TLV in ESADI-LSP
number zero. If it is missing from ESADI-LSP number zero or if ESADI-
LSP number zero is not known, priority for the sending RBridge
defaults to 0x40 and CSNP Time defaults to 30. If there is more than
one occurrence in ESADI-LSP number zero, the first occurrence will be
used. Occurrences of the ESADI parameter data APPsub-TLV in non-zero
ESADI-LSP fragments are ignored.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | (2 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | (2 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|R| Priority | (1 byte)
+-+-+-+-+-+-+-+-+
| CSNP Time | (1 byte)
+-+-+-+-+-+-+-+-+
| Flags | (1 byte)
+---------------+
| Reserved for expansion (variable)
+-+-+-+-...
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Figure 4. ESADI Parameter APPsub-TLV
Type: set to ESADI-PARAM subTLV (TRILL APPsub-TLV type 0x0001). Two
bytes because this APPsub-TLV appears in an Extended TLV [FS-LSP].
Length: Set to 3 to 65,535 but must fit within the ESADI packet.
R: A reserved bit that MUST be sent as zero and ignored on receipt.
Priority: The Priority field gives the originating RBridge's priority
for being DRB on the ESADI instance virtual link (see Section 3)
for the Data Label in which the PDU containing the parameter data
was sent. It is an unsigned seven-bit integer with larger
magnitude indication higher priority. It defaults to 0x40 for an
RBridge participating in ESADI for which it has not been
configured.
CSNP Time: An unsigned byte that gives the amount of time in seconds
during which the originating RBridge, if it is DRB on the ESADI
virtual link, will send at least three EASDI-CSNP PDUs. It
defaults to 30 seconds for an RBridge participating in ESADI for
which it has not been configured.
Flags: A byte of flags associated with the originating ESADI instance
as follows:
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+
| UN| RESV |
+---+---+---+---+---+---+---+---+
The UN flag indicates that the RBridge originating the ESADI-
LSP including this ESADI Parameter Data will accept and
properly process ESADI PDUs sent by TRILL unicast. The
remaining RESV bits are reserved for future use and MUST be
sent as zero and ignored on receipt.
Reserved for future expansion: Future versions of the ESADI
Parameters APPsub-TLV may have additional information. A receiving
ESADI RBridge ignores any additional data here unless it
implements such future expansion(s).
6.2 MAC Reachability TLV
The primary information in TRILL ESADI-LSP PDUs consists of MAC
Reachability (MAC-RI) TLVs specified in [RFC6165]. These TLVs
contain one or more unicast MAC addresses of end stations that are
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INTERNET-DRAFT TRILL: ESADI
both on a port and in a VLAN for which the originating RBridge is
appointed forwarder, along with the one octet unsigned Confidence in
this information with a value in the range 0-254. If such a TLV is
received with a confidence of 255, it is treated as if the confidence
was 254. (This is to assure that any received address information can
be overridden by local address information statically configured with
a Confidence of 255.)
The TLVs in TRILL ESADI PDUs, including the MAC-RI TLV, MUST NOT
contain the Data Label ID. If a Data Label ID is present in the MAC-
RI TLV, it is ignored. In the ESADI PDU, only the Inner.VLAN or
Inner.FGL tag indicates the Data Label to which the ESADI-LSP
applies.
6.3 Default Authentication
The Authentication TLV may be included in ESADI PDUs. The default for
ESADI PDU Authentication is based on the state of TRILL IS-IS shared
secret authentication for TRILL IS-IS LSP PDUs. If TRILL IS-IS
authentication and ESADI are implemented at a TRILL switch, then
ESADI MUST be able to use the authentication algorithms implemented
for TRILL IS-IS and implement the keying material derivation function
given below. If ESADI authentication has been manually configured,
that configuration is not restricted by the configuration of TRILL
IS-IS security.
If TRILL IS-IS authentication is not in effect for LSP PDUs
originated by a TRILL switch then, by default, ESADI PDUs originated
by that TRILL switch are also unsecured.
If such IS-IS LSP PDU authentication is in effect at a TRILL switch
then, unless configured otherwise, ESADI PDUs sent by that switch
MUST use the same algorithm in their Authentication TLVs. The ESADI
authentication keying material used is derived from the IS-IS LSP
shared secret keying material as detailed below. However, such
authentication MAY be configured to use some other keying material.
HMAC-SHA256 ( "TRILL ESADI", IS-IS-LSP-shared-key )
In the above HMAC-SHA256 is as described in [FIPS180] [RFC6234] and
"TRILL ESADI" is the eleven byte US ASCII [ASCII] string indicated.
IS-IS-LSP-shared-key is secret keying material being used by the
originating TRILL switch for IS-IS LSP authentication.
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7. IANA Considerations
IANA allocation and registry considerations are given below.
7.1 ESADI Participation and Capability Flags
IANA is requested to allocate bit TBD [3 recommended] as the "ESADI
Participation" bit in the Interested VLANs sub-TLV and the Interested
Labels sub-TLVs [rfc6326bis]. If The ESADI Participation bit is a
one, it indicates that the originating RBridge is participating in
ESADI for the indicated VLAN(s) or FGL(s). In addition, IANA is
requested to create two sub-registries in the TRILL Parameters
Registry for such bits as follows:
Sub-Registry: Interested VLANs Flag Bits
Registration Procedures: IETF Review
Note: These bits appear in the Interested VLANs record within the
Interested VLANs and Spanning Tree Roots Sub-TLV (INT-VLAN).
References: [rfc6326bis], [This document]
Bit Mnemonic Description Reference
--- -------- ----------- ---------
0 M4 IPv4 Multicast Router Attached [rfc6326bis]
1 M6 IPv6 Multicast Router Attached [rfc6326bis]
2 - available for allocation
3 ES ESADI Participation This document
4-15 - (used for a VLAN ID) [rfc6326bis]
16-19 - available for allocation
20-31 - (used for a VLAN ID) [rfc6326bis]
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INTERNET-DRAFT TRILL: ESADI
Sub-Registry: Interested Labels Flag Bits
Registration Procedures: IETF Review
Note: These bits appear in the Interested Labels record within the
Interested Labels and Spanning Tree Roots Sub-TLV (INT-LABEL).
References: [rfc6326bis], [this document]
Bit Mnemonic Description Reference
--- -------- ----------- ---------
0 M4 IPv4 Multicast Router Attached [rfc6326bis]
1 M6 IPv6 Multicast Router Attached [rfc6326bis]
2 BM Bit Map [rfc6326bis]
3 ES ESADI Participation This document
4-7 - available for allocation
7.2 TRILL GENINFO TLV
IANA is requested to allocate the IS-IS Application Identifier TBD [1
suggested] under the Generic Information TLV (#251) [RFC6823] for
TRILL and to create a subregistry in the TRILL Parameters Registry as
follows:
Sub-Registry: TRILL APPsub-TLV Types under IS-IS TLV #251
Application Identifier #TBD
Registration Procedures: IETF Review
Note: Types greater than 255 are only usable in contexts permitting a
type larger than one byte, such as Extended TLVs [FS-LSP].
Reference: <this RFC>
Type Name Reference
---------- -------- -----------
0 Reserved <this RFC>
1 ESADI-PARAM <this RFC>
2-254 Available <this RFC>
255 Reserved <this RFC>
256-65534 Available <this RFC>
65535 Reserved <this RFC>
TRILL APPsub-TLV Types 2 through 254 and 256 through 65534 are
available for assignment by IETF Review. The RFC causing such an
assignment will also include a discussion of security issues and of
the rate of change of the information being advertised. TRILL
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INTERNET-DRAFT TRILL: ESADI
APPsub-TLVs MUST NOT alter basic IS-IS protocol operation including
the establishment of adjacencies, the update process, and the
decision process for TRILL IS-IS [IS-IS] [RFC1195] [rfc6327bis]. The
TRILL Generic Information TLV MUST NOT be used in an IS-IS instance
zero [RFC6822].
The V, I, D, and S flags in the initial flags byte of a TRILL Generic
Information TLV have the meanings specified in [RFC6823] but are not
currently used as TRILL operates as a Level 1 IS-IS area and no
semantics are hereby assigned to the inclusion of an IPv4 and/or IPv6
address via the I and V flags. Thus these flags MUST be zero;
however, use of multi-level IS-IS is an obvious extension for TRILL
[MultiLevel] and future IETF Standards Actions may update or obsolete
this specification to provide for the use of any or all of these
flags in the TRILL GENINFO TLV.
The ESADI Parameters information, for which TRILL APPsub-TLV 1 is
hereby assigned, is compact and slow changing (see Section 6.1).
For Security Considerations related to ESADI and the ESADI parameters
APPsub-TLV, see Section 8.
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INTERNET-DRAFT TRILL: ESADI
8. Security Considerations
ESADI PDUs can be authenticated through the inclusion of the
Authentication TLV as described in Section 6.3. The ESADI-LSP data
primarily announces MAC&label reachability. Such reachability can, in
some cases, be an authenticated registration (for example, a layer 2
authenticated registration using cryptographically based EAP
(Extensible Authentication Protocol [RFC3748]) methods via [802.1X]).
The combination of these techniques can cause EASDI MAC reachability
information to be substantially more trustworthy than MAC
reachability learned from observation of the data plane.
Nevertheless, ESADI still involves trusting all other RBridges in the
TRILL campus.
MAC reachability learned from the data plane (the TRILL default) is
overwritten by any future learning of the same type. ESADI
advertisements are represented in data label scoped link state
database. Thus ESADI makes visible any multiple attachments of the
same MAC&label to different RBridges (see Section 5.3). This may or
may not be an error or misconfiguration but ESADI at least makes it
explicitly and persistently visible, which would not be the case with
data plane learning.
For general TRILL Security Considerations, see [RFC6325].
9. Acknowledgements
The authors thank the following, listed in alphabetic order, for
their suggestions and contributions:
Somnath Chatterjee, Thomas Narten, and Erik Nordmark
This document was produced with raw nroff. All macros used were
defined in the source file.
H. Zhai, et al [Page 27]
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Normative references
[ASCII] - American National Standards Institute (formerly United
States of America Standards Institute), "USA Code for
Information Interchange", ANSI X3.4-1968, 1968. ANSI X3.4-1968
has been replaced by newer versions with slight modifications,
but the 1968 version remains definitive for the Internet.
[FIPS180] - "Secure Hash Standard (SHS)", United States of American,
National Institute of Science and Technology, Federal
Information Processing Standard (FIPS) 180-4, March 2012,
http://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf
[IS-IS] - International Organization for Standardization,
"Intermediate system to Intermediate system intra-domain
routeing information exchange protocol for use in conjunction
with the protocol for providing the connectionless-mode Network
Service (ISO 8473)", ISO/IEC 10589:2002, Second Edition, Nov
2002.
[RFC1195] - Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
dual environments", RFC 1195, December 1990.
[RFC2119] - Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4086] - Eastlake 3rd, D., Schiller, J., and S. Crocker,
"Randomness Requirements for Security", BCP 106, RFC 4086, June
2005.
[RFC5226] - Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, May
2008.
[RFC6165] - Banerjee, A. and D. Ward, "Extensions to IS-IS for
Layer-2 Systems", RFC 6165, April 2011.
[RFC6325] - Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S., and A.
Ghanwani, "Routing Bridges (RBridges): Base Protocol
Specification", RFC 6325, July 2011.
[RFC6361] - Carlson, J. and D. Eastlake 3rd, "PPP Transparent
Interconnection of Lots of Links (TRILL) Protocol Control
Protocol", RFC 6361, August 2011.
[RFC6823] - Ginsberg, L., Previdi, S., and M. Shand, "Advertising
Generic Information in IS-IS", RFC 6823, December 2012.
[ClearCorrect] - Eastlake, D., Zhang, M., Ghanwani, A., Manral, V.,
A. Benerjee, "TRILL: Clarifications, Corrections, and Updates",
H. Zhai, et al [Page 28]
INTERNET-DRAFT TRILL: ESADI
draft-ietf-trill-clear-correct, in RFC Editor's queue.
[FS-LSP] - Ginsberg, L., S. Previdi, Y. Yang, "IS-IS Flooding Scope
LSPs", draft-ietf-isis-fs-lsp, work in progress.
[rfc6326bis] - Eastlake, D., Senevirathne, T., Ghanwani, A., Dutt,
D., and A. Banerjee, "Transparent Interconnection of Lots of
Links (TRILL) Use of IS-IS", draft-ietf-isis-rfc6326bis, work
in progress.
[rfc6327bis] - Eastlake 3rd, D., Perlman, R., Ghanwani, A., Yang, H.,
and V. Manral, "Routing Bridges (RBridges): Adjacency", draft-
ietf-trill-rfc6327bis, work in progress.
[RFCfgl] - Eastlake, D., M. Zhang, P. Agarwal, R. Perlman, D. Dutt,
"TRILL (Transparent Interconnection of Lots of Links): Fine-
Grained Labeling", draft-ietf-trill-fine-labeling, in RFC
Ediotr's queue.
Informative References
[802.1X] - IEEE 802.1, "IEEE Standard for Local and metropolitan area
networks / Port-Based Network Access Control", IEEE Std
802.1X-2010, 5 February 2010.
[RFC3748] - Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., and H.
Levkowetz, Ed., "Extensible Authentication Protocol (EAP)", RFC
3748, June 2004.
[RFC6234] - Eastlake 3rd, D. and T. Hansen, "US Secure Hash
Algorithms (SHA and SHA-based HMAC and HKDF)", RFC 6234, May
2011.
[RFC6822] - Previdi, S., Ed., Ginsberg, L., Shand, M., Roy, A., and
D. Ward, "IS-IS Multi-Instance", RFC 6822, December 2012.
[MultiLevel] - Perlman, R., D. Eastlake, A. Ghanwani, H. Zhai,
"Multilevel TRILL (Transparent Interconnection of Lots of
Links)", draft-perlman-trill-rbridge-multilevel, work in
progress.
[VLANmapping] - Perlman, R., D. Dutt, A. Banerjee, A. Rijhsinghani,
and D. Eastlake, "RBridges: Campus VLAN and Priority Regions",
draft-ietf-trill-rbridge-vlan-mapping, work in progress.
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Appendix A: Changes to [RFC6325]
Below is a list of the main changes this document makes to the TRILL
base protocol specification [RFC6325]:
1. The format of ESADI-LSP, ESDAI-CSNP, and ESADI-PSNP PDU payloads
is changed from the base IS-IS format to the Extended Level 1
Circuit Scoped format in [FS-LSP].
2. Unicasting of ESADI PDUs is supported.
3. The handling of persistent reachability of the same MAC within the
same Data Label from two or more RBridge is substantially modified
(see Section 5.3).
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Appendix Z: Change History
RFC Editor: Please delete this section before publication.
Z.1 From -00 to -01
1. Add Section 6.3 "Default Authentication".
2. Add "Acknowledgements" Section.
3. Change requirement from "MAY" to "SHOULD" for an ESADI RBridge
that is not DRB to send an ESADI-CSNP if it does not receive an
ESADI-CSNP in long enough.
4. Default CSNP Time was listed as 30 in one place and 40 in another.
Change to uniformly specify 30.
5. Update references to RFC 6326 to reference the 6326bis draft.
6. Relax allocation criteria for TRILL APPsub-TLV type code points
from Standard Action to IETF Review.
7. Numerous Editorial changes.
Z.2 From -01 to -02
1. Extend to cover FGL and well as VLAN and introduce the term "Data
Label" to cover both.
2. Expand number of LSP fragments to 2**16.
3. Simplify neighbor detection to no longer require possession of
ESADI LSP zero.
4. Add update to last sentence of Section 4.2 of [RFC6325].
5. Update references for publication of RFCs 6822 and 6823.
6. Additional minor changes.
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Z.3 From -02 to -03
1. Replace instances of "IS-IS and data unreachable" with just "data
unreachable" as data unreachability implies IS-IS unreachability
[ClearCorrect].
2. With ESADI, there is just one virtual link on which all
participating TRILL switches are adjacent. Thus, all of the useful
ESADI-LSPs in an ESADI link state database are originated by a
station on this virtual link. To avoid overworking the ESADI DRB
on the link, ESADI-LSPs sent by a reachable TRILL switch in
response to an ESADI-PSNP should be sent by the TRILL switch
originating those EASDI-LSPs.
3. Re-organize material on sending and receiving ESADI PDUs into more
smaller subsections that cover all the different circumstances.
4. Substantially expand Security Considerations section.
5. Numerous editorial changes.
Z.4 From -03 to -04
1. Change to using Extended Level 1 Circuit Scope [FS-LSP] for EASDI-
LSP, ESADI-CSNP, and ESDAI-PSNP PDUs.
2. Update references to RFC 6327 to the rfc6327bis draft.
3. Sort Informational References RFCs in numeric order.'
4. Add Appendix A: summary of changes to [RFC6325].
5. Minor editing changes.
H. Zhai, et al [Page 32]
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Authors' Addresses
Hongjun Zhai
ZTE Corporation
68 Zijinghua Road
Nanjing 200012 China
Phone: +86-25-52877345
Email: zhai.hongjun@zte.com.cn
Fangwei Hu
ZTE Corporation
889 Bibo Road
Shanghai 201203 China
Phone: +86-21-68896273
Email: hu.fangwei@zte.com.cn
Radia Perlman
Intel Labs
2200 Mission College Blvd.
Santa Clara, CA 95054-1549 USA
Phone: +1-408-765-8080
Email: Radia@alum.mit.edu
Donald Eastlake
Huawei R&D USA
155 Beaver Street
Milford, MA 01757 USA
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H. Zhai, et al [Page 33]
INTERNET-DRAFT TRILL: ESADI
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H. Zhai, et al [Page 34]