Internet DRAFT - draft-ietf-trill-ia-appsubtlv
draft-ietf-trill-ia-appsubtlv
INTERNET-DRAFT Donald Eastlake
Intended status: Proposed Standard Yizhou Li
Huawei
Expires: December 1, 2016 June 2, 2016
TRILL: Interface Addresses APPsub-TLV
<draft-ietf-trill-ia-appsubtlv-08.txt>
Abstract
This document specifies a TRILL (Transparent Interconnection of Lots
of Links) IS-IS application sub-TLV that enables the reporting by a
TRILL switch of sets of addresses. Each set of addresses reports all
of the addresses that designate the same interface (port) and also
reports the TRILL switch by which that interface is reachable. For
example, a 48-bit MAC (Media Access Control) address, IPv4 address,
and IPv6 address can be reported as all corresponding to the same
interface reachable by a particular TRILL switch. Such information
could be used in some cases to synthesize responses to or bypass the
need for the Address Resolution Protocol (ARP), the IPv6 Neighbor
Discovery (ND) protocol, or the flooding of unknown MAC addresses.
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.
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.
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.
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Table of Contents
1. Introduction............................................3
1.1 Conventions Used in This Document......................3
2. Format of the Interface Addresses APPsub-TLV............5
3. IA APPsub-TLV sub-sub-TLVs.............................10
3.1 AFN Size sub-sub-TLV..................................10
3.2 Fixed Address sub-sub-TLV.............................11
3.3 Data Label sub-sub-TLV................................12
3.4 Topology sub-sub-TLV..................................13
4. Security Considerations................................14
5. IANA Considerations....................................15
5.1 AFN Number Allocation.................................15
5.2 IA APPsub-TLV Sub-Sub-TLVs SubRegistry................15
5.3 IA APPsub-TLV Number..................................16
6. Processing Address Sets................................17
Acknowledgments...........................................18
Appendix A: Examples......................................19
A.1 Simple Example........................................19
A.2 Complex Example.......................................19
Appendix Z: Change History................................22
Normative References......................................23
Informational References..................................24
Authors' Addresses........................................25
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1. Introduction
This document specifies a TRILL (Transparent Interconnection of Lots
of Links) [RFC6325] IS-IS application sub-TLV (APPsub-TLV [RFC6823])
that enables the convenient representation of sets of addresses where
all of the addresses in each set designate the same interface (port).
For example, a 48-bit MAC (Media Access Control [RFC7042]) address,
IPv4 address, and IPv6 address can be reported as all three
designating the same interface. In addition, a Data Label (VLAN or
Fine Grained Label (FGL [RFC7172])) is specified for the interface
along with the TRILL switch, and optionally the TRILL switch port,
from which the interface is reachable. Such information could be
used in some cases to synthesize responses to or bypass the need for
the Address Resolution Protocol (ARP [RFC826]), the IPv6 Neighbor
Discovery (ND [RFC4861]) protocol, the Reverse Address Resolution
Protocol (RARP [RFC903]), or the flooding of unknown destination MAC
addresses [ARPND]. If the information reported is complete, it can
also be used to detect and discard packets with forged source
addresses.
This APPsub-TLV appears inside the TRILL GENINFO TLV specified in the
ESADI RFC [RFC7357] but may also occur in other application contexts.
Directory Assisted TRILL Edge services [DirectoryScheme] are expected
to make use of this APPsub-TLV.
Although, in some IETF protocols, address field types are represented
by Ethertype [RFC7042] or Hardware Type [RFC5494], only Address
Family Number (AFN) is used in this APPsub-TLV to represent address
field type.
1.1 Conventions Used in This Document
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 Considerations terms such as "Expert Review" are to be
interpreted as described in [RFC5226].
The terminology and acronyms of [RFC6325] are used herein along with
the following additional acronyms and terms:
AFN: Address Family Number
(http://www.iana.org/assignments/address-family-
numbers/address-family-numbers.xhtml)
APPsub-TLV: Application sub-TLV [RFC6823]
Data Label: VLAN or FGL
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FGL: Fine Grained Label [RFC7172]
IA: Interface Address(es)
Nickname: A 16-bit TRILL switch identifier as specified in Section
3.7 of [RFC6325] as updated by Section 4 of [RFC7780].
RBridge: An alternative name for a TRILL switch
TRILL switch: A device that implements the TRILL protocol
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2. Format of the Interface Addresses APPsub-TLV
The Interface Addresses (IA) APPsub-TLV is used to advertise a set of
addresses indicating the same interface (port) within a Data Label
(VLAN or FGL). It also associates that interface with the TRILL
switch, and optionally the TRILL switch port, by which the interface
is reachable. These addresses can be in different address families.
For example, it can be used to declare that a particular interface
with specified IPv4, IPv6, and 48-bit MAC addresses in some
particular Data Label is reachable from a particular TRILL switch.
While those three types of address are likely to be the only types of
interest, any address type for which an AFN (Address Family Number)
has been assigned by IANA can be represented.
The Template field in a particular IA APPsub-TLV indicates the format
of each Address Set it carries. Certain well-known sets of addresses
are represented by special values. Other sets of addresses are
specified by a list of AFNs. The Template format that uses a list of
AFNs provides an explicit pattern for the type and order of addresses
in each Address Set in the IA APPsub-TLV that includes that Template.
A device or application making use of IA APPsub-TLV data is not
required to make use of all IA data. For example, a device or
application that was only interested in MAC and IPv6 addresses could
ignore any IPv4 or other types of address information that was
present.
The figure below shows an IA APPsub-TLV as it would appear inside an
IS-IS FS-LSP using an extended flooding scope [RFC7356] TLV, for
example in ESADI [RFC7357]. Within an IS-IS FS-LSP using traditional
[ISO-10589] TLVs, the Type and Length would be one byte unsigned
integers equal to or less than 255 but with an extended TLV the Type
and Length are a two byte unsigned integer.
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = (TBD) | (2 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | (2 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Addr Sets End | (2 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Nickname | (2 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | (1 byte)
+-+-+-+-+-+-+-+-+
| Confidence | (1 byte)
+-+-+-+-+-+-+-+-+-+-
| Template ... (variable)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+
| Address Set 1 (size determined by Template) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+
| Address Set 2 (size determined by Template) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+
| ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+
| Address Set N (size determined by Template) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+
| optional sub-sub-TLVs ...
+-+-+-+-+-+-+-+-+-+-+-+-...
Figure 1. The Interface Addresses APPsub-TLV
o Type: Interface Addresses TRILL APPsub-TLV type, set to (TBD) (IA-
SUBTLV).
o Length: Variable, minimum 7. If length is 6 or less or if the
APPsub-TLV extends beyond the size of an encompassing TRILL
GENINFO TLV or other context, the APPsub-TLV MUST be ignored. For
manageability, a counter should be maintained of receipt of such
malformed IA APPsub-TLVs.
o Addr Sets End: The unsigned integer offset of the byte, within the
IA APPsub-TLV value part, of the last byte of the last Address
Set. This will be the byte just before the first sub-sub-TLV if
any sub-sub-TLVs are present (see Section 3). The processing is as
follows:
- If this field is greater than Length or points to before the
end of the Template, the IA APPsub-TLV is corrupt and MUST be
discarded.
- If this field is equal to Length, there are no sub-sub-TLVs.
- If this field is less than Length, sub-sub-TLVs are parsed as
specified in Section 3.
Note: This field is always two bytes in size.
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o Nickname: The nickname (see Section 1.1) of the TRILL switch by
which the address sets are reachable. If zero, the address sets
are reachable from the TRILL switch originating the message
containing the APPsub-TLV (for example, an ESADI [RFC7357]
message).
o Flags: A byte of flags as follows:
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
|D|L| RESV |
+-+-+-+-+-+-+-+-+
D: Directory flag: If D is one, the APPsub-TLV contains
Directory information [RFC7067].
L: Local flag: If L is one, the APPsub-TLV contains information
learned locally by observing ingressed frames [RFC6325].
(Both D and L can be set to one in the same IA APPsub-TLV if
a TRILL switch that had learned an address locally and also
advertised it as a directory.)
RESV: Additional reserved flag bits that MUST be sent as zero
and ignored on receipt.
o Confidence: This 8-bit unsigned quantity in the range 0 to 254
indicates the confidence level in the addresses being transported
(see Section 4.8.2 of [RFC6325]). A value of 255 is treated as if
it was 254.
o Template: The initial byte of this field is the unsigned integer
K. If K has a value from 1 to 31, it indicates that this initial
byte is followed by a list of K AFNs (Address Family Numbers) that
specify the exact structure and order of each Address Set
occurring later in the APPsub-TLV. K can be 1, which is the
minimum valid value. If K is zero, the IA APPsub-TLV is ignored.
If K is 32 to 254, the length of the Template field is one byte
and its value is intended to correspond to a particular ordered
set of AFNs some of which are specified below. The value of 255
for K is reserved for future definition and causes the IA APPsub-
TLV to be ignored.
If the Template uses explicit AFNs, it looks like the following,
with the number of AFNs, up to 31, equal to K.
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+-+-+-+-+-+-+-+-+
| K | (1 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFN 1 | (2 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFN 2 | (2 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFN K | (2 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
For K in the 32 to 39 range, values indicate a specific sequence
as specified below. The values of K from 40 to 254 are reserved
for future such specification. If the value of K is not understood
by a receiver of the IA-APPsub-TLV, any Address Sets present are
ignored.
K Addresses in order of occurrence
--- --------------------------------
32 48-bit MAC
33 48-bit MAC, IPv4
34 48-bit MAC, IPv6
35 48-bit MAC, IPv4, IPv6
36 48-bit MAC, RBridge port
37 48-bit MAC, IPv4, RBridge port
38 48-bit MAC, IPv6, RBridge port
39 48-bit MAC, IPv4, IPv6, RBridge port
For ease of decoding, note that for values of K between 32 and 39
inclusive, the 0x01 bit indicates an IPv4 address is present, the
0x02 bit indicates an IPv6 address is present, and the 0x04 bit
indicates that an RBridge port ID is present.
o AFN: A two-byte Address Family Number. The number of AFNs present
is given by K except that there are no AFNs if K is greater than
31. The AFN sequence specifies the structure of the Address Sets
occurring later in the TLV. For example, if Template Size is 2 and
the two AFNs present are the AFNs for a 48-bit MAC and an IPv4
address, in that order, then each Address set present will consist
of a 6-byte MAC address followed by a 4-byte IPv4 address. If any
AFNs are present that are unknown to the receiving IS and the
length of the corresponding address is not provided by a sub-sub-
TLV as specified below, the receiving IS will be unable to parse
the Address Sets and MUST ignore the IA APPsub-TLV.
o Address Set: Each address set in the APPsub-TLV consists of
exactly the same sequence of addresses and types as specified by
the Template earlier in the APPsub-TLV. No alignment, other than
to a byte boundary, is provided. The addresses in each Address Set
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are contiguous with no unused bytes between them and the Address
Sets are contiguous with no unused bytes between successive
Address Sets. The Address Sets must fit within the TLV. See
Section 6 on interpreting certain Address Sets.
o sub-sub-TLVs: If the Address Sets indicated by Addr Sets End do
not completely fill the Length of the APPsub-TLV, the remaining
bytes are parsed as sub-sub-TLVs [RFC5305]. Any such sub-sub-TLVs
that are not known to the receiving TRILL switch are ignored.
Should this parsing not be possible, for example there is only one
remaining byte or an apparent sub-sub-TLV extends beyond the end
of the TLV, the containing IA APPsub-TLV is considered corrupt and
is ignored. (Several sub-sub-TLV types are specified in Section
3.)
Different IA APPsub-TLVs within the same or different LSPs or other
data structures may have different Templates. The same AFN may occur
more than once in a Template and the same address may occur in
different address sets. For example, a 48-bit MAC address interface
might have three different IPv6 addresses. This could be represented
by an IA APPsub-TLV whose Template specifically provided for one
EUI-48 address and three IPv6 addresses, which might be an efficient
format if there were multiple interfaces with that pattern.
Alternatively, a Template with one 48-bit MAC and one IPv6 address
could be used in an IA APPsub-TLV with three address sets each having
the same MAC address but different IPv6 addresses, which might be the
most efficient format if only one interface had multiple IPv6
addresses and other interfaces had only one IPv6 address.
In order to be able to parse the Address Sets, a receiving TRILL
switch must know at least the size of the address for each AFN or
address type the Template specifies; however, the presence of the
Addr Set End field means that the sub-sub-TLVs, if any, can always be
located by a receiver. A TRILL switch can be assumed to know the
size of the AFNs mentioned in Section 5. Should a TRILL switch wish
to include an AFN that some receiving TRILL switch in the campus may
not know, it SHOULD include an AFN-Size sub-sub-TLV as described in
Section 3.1. If an IA APPsub-TLV is received with one or more AFNs in
its template for which the receiving TRILL switch does not know the
length and for which an AFN-Size sub-sub-TLV is not present, that IA
APPsub-TLV MUST be ignored.
For manageability, a counter should be maintained of ill-formed IA
APPsub-TLVs received and ignored due to unknown K, unknown AFN, and
the like, as described above.
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3. IA APPsub-TLV sub-sub-TLVs
IA APPsub-TLVs can have trailing sub-sub-TLVs [RFC5305] as specified
below. These sub-sub-TLVs occur after the Address Sets and the
amount of space available for sub-sub-TLVs is determined from the
overall IA APPsub-TLV length and the value of the Addr Set End byte.
There is no ordering restriction on sub-sub-TLVs. Unless otherwise
specified each sub-sub-TLV type can occur zero, one, or many times in
an IA APPsub-TLV. Any sub-sub-TLVs for which the Type is unknown are
ignored. For manageability, a counter should be maintained of sub-
sub-TLVs received and ignored due to unknown Type or other reasons
described below.
The sub-sub-TLVs data structures shown below, with two byte Types and
Lengths, assume that the enclosing IA APPsub-TLV is in an extended
LSP TLV [RFC7356] or some non-LSP context. If they were used in a IA
APPsub-TLV in a non-extended LSP [ISO-10589], then only one byte
Types and Lengths could be used. As a result, any sub-sub-TLV types
greater than 255 could not be used and Length would be limited to
255.
3.1 AFN Size sub-sub-TLV
Using this sub-sub-TLV, the originating TRILL switch can specify the
size of an address type. This is useful under two circumstances as
follows:
1. One or more AFNs that are unknown to the receiving TRILL switch
appears in the template. If an AFN Size sub-sub-TLV is present for
each such AFN, then at least the IA APPsub-TLV can be parsed and
possibly other addresses in each address set can still be used.
2. If an AFN occurs in the Template that represents a variable length
address, this sub-sub-TLV gives its size for all occurrences in
that IA APPsub-TLV.
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = AFNsz | (2 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | (2 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFN Size Record 1 | (3 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFN Size Record 2 | (3 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFN Size Record N | (3 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2. AFN Size sub-sub-TLV
Where each AFN Size Record is structured as follows:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFN | (2 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AdrSize | (1 byte)
+-+-+-+-+-+-+-+-+
o Type: AFN-Size sub-sub-TLV type, set to 1 (AFNsz).
o Length: 3*n where n is the number of AFN Size Records present. If
Length is not a multiple of 3, the sub-sub-TLV MUST be ignored.
o AFN Size Record(s): Zero or more 3-byte records, each giving the
size of an address type identified by an AFN,
o AFN: The AFN whose length is being specified by the AFN Size
Record.
o AdrSize: The length in bytes of addresses specified by the AFN
field as an unsigned integer.
An AFN Size sub-sub-TLV for any AFN known to the receiving TRILL
switch is compared with the size known to the TRILL switch. If they
differ the IA APPsub-TLV is assumed to be corrupt and MUST be
ignored.
3.2 Fixed Address sub-sub-TLV
There may be cases where, in a particular Interface Addresses (IA)
APPsub-TLV, the same address would appear in every address set across
the IA APPsub-TLV. To avoid wasted space, this sub-sub-TLV can be
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used to indicate such a fixed address. The address or addresses
incorporated into the sets by this sub-sub-TLV are NOT mentioned in
the IA APPsub-TLV Template.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=FIXEDADR | (2 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | (2 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFN | (2 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Fixed Address (variable)
+-+-+-+-+-+-+-+-+-+-+-+-+-...
Figure 3. Fixed Address sub-sub-TLV
o Type: Data Label sub-sub-TLV type, set to 2 (FIXEDADR).
o Length: variable, minimum 2. If Length is 0 or 1, the sub-sub-TLV
MUST be ignored.
o AFN: Address Family Number of the Fixed Address.
o Fixed Address: The address of the type indicated by the preceding
AFN field that is considered to be part of every Address Set in
the IA APPsub-TLV.
The Length field implies a size for the Fixed Address. If that size
differs from the size of the address type for the given AFN as known
by the receiving TRILL switch, the Fixed Address sub-sub-TLV is
considered corrupt and MUST be ignored.
3.3 Data Label sub-sub-TLV
This sub-sub-TLV indicates the Data Label within which the interfaces
listed in the IA APPsub-TLV are reachable. It is useful if the IA
APPsub-TLV occurs outside of the context of a message specifying the
Data Label or if it is desired and permitted to override that
specification. Multiple occurrences of this sub-sub-TLV indicate
that the interfaces are reachable in all of the Data Labels given.
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Type=DATALEN | (2 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | (2 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Label (variable)
+-+-+-+-+-+-+-+-+-+-+-+-+-...
Figure 4. Data Label sub-sub-TLV
o Type: Data Label sub-TLV type, set to 3 (LABEL).
o Length: 2 or 3. If Length is some other value, the sub-sub-TLV
MUST be ignored.
o Data Label: If length is 2, the bottom 12 bits of the Data
Label are a VLAN ID and the top 4 bits are reserved (MUST be
sent as zero and ignored on receipt). If the length is 3, the
three Data Label bytes contain an FGL [RFC7172].
3.4 Topology sub-sub-TLV
The presence of this sub-sub-TLV indicates that the interfaces given
in the IA APPsub-TLV are reachable in the topology given. It is
useful if the IA APPsub-TLV occurs outside of the context of a
message indicating the topology or if it is desired and permitted to
override that specification. If it occurs multiple times, then the
Address Sets are in all of the topologies given.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Type=TOPOLOGY | (2 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | (2 byte)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RESV | Topology | (2 bytes)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5. Topology sub-sub-TLV
o Type: Topology sub-TLV type, set to 4 (TOPOLOGY).
o Length: 2. If Length is some other values, the sub-sub-TLV MUST
be ignored.
o RESV: Four reserved bits. MUST be sent as zero and ignored on
receipt.
o Topology: The 12-bit topology number [RFC5120].
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4. Security Considerations
The integrity of address mapping and reachability information and the
correctness of Data Labels (VLANs or FGLs [RFC7172]) are very
important. Forged, altered, or incorrect address mapping or Data
Labeling can lead to delivery of packets to the incorrect party,
violating security policy. However, this document merely describes a
data format and does not provide any explicit mechanisms for securing
that information, other than a few simple consistency checks that
might detect some corrupted data. Security on the wire, or in
storage, for this data is to be providing by the transport or storage
used. For example, when transported with ESADI [RFC7357] or RBridge
Channel [RFC7178], ESADI security or Channel Tunnel [ChannelTunnel]
security mechanisms can be used, respectively.
The address mapping and reachability information, if known to be
complete and correct, can be used to detect some cases of forged
packet source addresses [RFC7067]. In particular, if native traffic
from an end station is received by a TRILL switch that would
otherwise accept it but authoritative data indicates the source
address should not be reachable from the receiving TRILL switch, that
traffic should be discarded. The data format specified in this
document may optionally include TRILL switch Port ID number so that
this forged address filtering can be optionally applied with port
granularity. For manageability, a counter should be maintained of
frames so discarded.
See [RFC6325] for general TRILL Security Considerations.
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5. IANA Considerations
The following subsections specify IANA actions.
5.1 AFN Number Allocation
IANA has allocated the following AFN values that may be useful for IA
APPsub-TLVs:
Hex Decimal Description References
----- ------- ----------- ----------
0001 1 IPv4
0002 2 IPv6
4005 16389 48-bit MAC [RFC7042]
4006 16390 64-bit MAC [RFC7042]
4007 16391 OUI This document.
4008 16392 MAC/24 This document.
4009 16393 MAC/40 This document.
400A 16394 IPv6/64 This document.
400B 16395 RBridge Port ID This document.
Other AFNs can be found at http://www.iana.org/assignments/address-
family-numbers
See Section 6 on interpreting address sets.
5.2 IA APPsub-TLV Sub-Sub-TLVs SubRegistry
IANA is requested to establish a new subregistry of the TRILL
Parameter Registry for sub-sub-TLVs of the Interface Addresses
APPsub-TLV with initial contents as shown below.
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Name: Interface Addresses APPsub-TLV Sub-Sub-TLVs
Procedure: Expert Review
Note: Types greater than 255 are not usable in some contexts.
Reference: [This document]
Type Description Reference
------ ----------- ---------
0 Reserved
1 AFN Size [This document]
2 Fixed Address [This document]
3 Data Label [This document]
4 Topology [This document]
5-254 Unassigned
255 Reserved
256-65534 Unassigned
65535 Reserved
5.3 IA APPsub-TLV Number
IANA is requested to allocate (TBD) as the Type for the IA APPsub-TLV
in the "TRILL APPsub-TLV Types under IS-IS TLV 251 Application
Identifier 1" registry from the range under 256. In the registry the
Name is "IA" and the Reference is this document.
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6. Processing Address Sets
The following processes should be followed in interpreting sets of
addresses in an IA APPsub-TLV:
The OUI AFN is provided so that MAC addresses can be abbreviated if
they have the same upper 24 bits. A MAC/24 is a 24-bit suffix
intended to be pre-fixed by an OUI to create a 48-bit MAC address
[RFC7042]; in the absence of an OUI, a MAC/24 entry cannot be used.
A MAC/40 is a suffix intended to be pre-fixed by an OUI to create a
64-bit MAC address [RFC7042]; in the absence of an OUI, a MAC/40
entry cannot be used.
Typically, an OUI would be provided as a Fixed Address sub-sub-TLV
(see Section 3.2) using the OUI AFN.
After Fixed Address sub-sub-TLV processing, each address set is
processed by combining each OUI in the address set with each MAC/24
and each MAC/40 address in the address set. Depending on how many of
each of these address types is present, zero or more 48-bit and/or
64-bit MAC addresses may be produced that are considered to be part
of the address set. If there are no MAC/24 or MAC/40 addresses
present, any OUI's are ignored. If there are no OUIs, any MAC/24
and/or MAC/40s are ignored. If there are K1 OUIs, K2 MAC/24s, and K3
MAC/40s, K1*K2 48-bit MACs are synthesized and K1*K3 64-bit MACs are
synthesized.
IPv6/64 is an 8-byte quantity that is the first 64 bits of an IPv6
address. IPv6/64s are ignored unless, after the processing above in
this sub-section, there are one or more 48-bit and/or 64-bit MAC
addresses in the address set to provide the lower 64 bits of the IPv6
address. For this purpose, an 48-bit MAC address is expanded to 64
bits as described in [RFC7042]. If there are K4 IPv6/64s present and
K5 48- and 64-bit MAC addresses present, K4*K5 128-bit IPv6 addresses
are synthesized.
D. Eastlake and Y Li [Page 17]
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Acknowledgments
The authors gratefully acknowledge the contributions and review by
the following:
Linda Dunbar, Sue Hares, Danny McPherson, and Gayle Noble
The document was prepared in raw nroff. All macros used were defined
within the source file.
D. Eastlake and Y Li [Page 18]
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Appendix A: Examples
Below are example IA APPsub-TLVs. "0x" indicates that the following
quantity is in hexadecimal. "0b" indicates that the following
quantity is in binary. Leading zeros are retained.
A.1 Simple Example
Below is an annotated IA APPsub-TLV carrying two simple pairs of
EUI-48 MAC addresses and IPv4 addresses from a Push Directory
[RFC7067]. No sub-sub-TLVs are included.
0x0002(TBD) Type: Interface Addresses
0x001B Length: 27 (=0x1B)
0x001B Address Sets End: 27 (=0x1B)
0x1234 RBridge Nickname from which reachable
0b10000000 Flags: Push Directory data
0xE3 Confidence = 227
33 Template: 33 (0x21) = 32 + 1(IPv4)
Address Set One
0x00005E0053A9 48-bitMAC address
198.51.100.23 IPv4 address
Address Set Two
0x00005E00536B 48-bit MAC address
203.0.113.201 IPv4 address
Size includes 7 for the fixed fields though and including the one
byte template, plus 2 times the Address Set size. Each Address Set is
10 bytes, 6 for the 48-bit MAC address plus 4 for the IPv4 address.
So total size is 7 + 2*10 = 27.
See Section 2 for more information on Template.
A.2 Complex Example
Below is an annotated IA APPsub-TLV carrying three sets of addresses,
each consisting of an EUI-48 MAC address, an IPv4 addresses, an IPv6
address, and an RBridge Port ID, all from a Push Directory [RFC7067].
The IPv6 address for each address set is synthesized from the MAC
address given in that set and the IPv6/64 64-bit prefix provided
through a Fixed Address sub-sub-TLV. In addition, a sub-sub-TLV is
included that provides an FGL which overrides whatever Data Label may
be provided by the envelope (for example an ESADI-LSP [RFC7357])
within which this IA APPsub-TLV occurs.
D. Eastlake and Y Li [Page 19]
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0x0002(TBD) Type: Interface Addresses
0x0036 Length: 54 (=0x36)
0x0021 Address Sets End: 33 (=0x21)
0x4321 RBridge Nickname from which reachable
0b10000000 Flags: Push Directory data
0xD3 Confidence = 211
37 Template: 37(0x25)=32+1(IPv4)+4(Port)
Address Set One
0x00005E0053DE 48-bitMAC address
198.51.100.105 IPv4 address
0x1DE3 RBridge Port ID
Address Set Two
0x00005E0053E3 48-bit MAC address
203.0.113.89 IPv4 address
0x1DEE RBridge Port ID
Address Set Three
0x00005E0053D3 48-bit MAC address
192.0.2.139 IPv4 address
0x01DE RBridge Port ID
sub-sub-TLV One
0x0003 Type: Data Label
0x0003 Length: implies FGL
0xD3E3E3 Fine Grained Label
sub-sub-TLV Two
0x0002 Type: Fixed Address
0x000A Size: 0x0A = 10
0x400A AFN: IPv6/64
0x20010DB800000000 IPv6 Prefix: 2001:DB8::
See Section 2 for more information on Template.
The Fixed Address sub-sub-TLV causes the IPv6/64 value given to be
treated as if it occurred as a 4th entry inside each of the three
Address Sets. When there is an IPv6/64 entry and a 48-bit MAC entry,
the MAC value is expanded by inserting 0xFFFE immediately after the
OUI and the resulting 64-bit value is used as the lower 64 bits of
the resulting IPv6 address [RFC7042]. As a result, a receiving TRILL
switch would treat the three Address Sets shown as if they had an
IPv6 address in them as follows:
D. Eastlake and Y Li [Page 20]
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Address Set One
0x20010DB80000000000005EFFFE0053DE IPv6 Address
Address Set Two
0x20010DB80000000000005EFFFE0053E3 IPv6 Address
Address Set Three
0x20010DB80000000000005EFFFE0053D3 IPv6 Address
As an alternative to the compact "well know value" Template encoding
used in this example above, the less compact explicit AFN encoding
could have been used. In that case, the IA APPsub-TLV would have
started as follows:
0x0002(TBD) Type: Interface Addresses
0x003C Length: 60 (=0x3C)
0x0027 Address Sets End: 39 (=0x27)
0x4321 RBridge Nickname from which reachable
0b10000000 Flags: Push Directory data
0xD3 Confidence = 211
0x3 Template: 3 AFNs
0x4005 AFN: 48-bit MAC
0x0001 AFN: IPv4
0x400B AFN: RBridge Port ID
As a final point, since the 48-bit MAC addresses in these three
Address Sets all have the same OUI (the IANA OUI [RFC7042]), it would
have been possible to just have a MAC/24 value giving the lower 24
bits of the MAC in each Address Set. The OUI would them be supplied
by a second Fixed Address sub-sub-TLV proving the OUI. With N Address
Sets, this would have saved 3*N or 9 bytes in this case at the cost
of 9 bytes (2 each for the type and length of the sub-sub-TLV, 2 for
the OUI AFN number, and 3 for the OUI). So, with just three Address
Sets, there would be no net saving; however, with a larger number of
Address Sets, there would be a net savings.
D. Eastlake and Y Li [Page 21]
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Appendix Z: Change History
From -00 to -01
1. Update references for RFC publications.
2. Add this Change History Appendix.
From -01 to -02
1. Fix off-by-one errors in body text and examples for well known
Template values.
2. Update for drafts published as RFCs and change in Author Address.
3. Minor editorial improvements.
From -02 to -03
Minor editorial improvements.
From -03 to -04
Editorial improvements.
From -04 to -05
Remove one author.
From -05 to -06
Update for Shepherd review. Simplify Template for values of K over
31. Editorial improvements.
From -06 to -07
Add Acknowledgement. Remove one unused reference and add and refer to
a replacement reference.
From -07 to -08
Update based on Routing Directorate review.
D. Eastlake and Y Li [Page 22]
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Normative References
[ISO-10589] - ISO/IEC 10589:2002, Second Edition, "Intermediate
System to Intermediate System Intra-Domain Routing Exchange
Protocol for use in Conjunction with the Protocol for Providing
the Connectionless-mode Network Service (ISO 8473)", 2002.
[RFC826] - Plummer, D., "An Ethernet Address Resolution Protocol",
RFC 826, November 1982.
[RFC903] - Finlayson, R., Mann, T., Mogul, J., and M. Theimer, "A
Reverse Address Resolution Protocol", STD 38, RFC 903, June
1984.
[RFC2119] - Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997
[RFC4861] - Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
September 2007.
[RFC5120] - Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
Topology (MT) Routing in Intermediate System to Intermediate
Systems (IS-ISs)", RFC 5120, February 2008.
[RFC5226] - Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, May
2008.
[RFC5305] - Li, T. and H. Smit, "IS-IS Extensions for Traffic
Engineering", RFC 5305, October 2008.
[RFC6325] - Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S., and A.
Ghanwani, "Routing Bridges (RBridges): Base Protocol
Specification", RFC 6325, July 2011.
[RFC6823] - Ginsberg, L., Previdi, S., and M. Shand, "Advertising
Generic Information in IS-IS", RFC 6823, December 2012.
[RFC7042] - Eastlake 3rd, D. and J. Abley, "IANA Considerations and
IETF Protocol and Documentation Usage for IEEE 802 Parameters",
BCP 141, RFC 7042, October 2013.
[RFC7172] - Eastlake 3rd, D., Zhang, M., Agarwal, P., Perlman, R.,
and D. Dutt, "Transparent Interconnection of Lots of Links
(TRILL): Fine-Grained Labeling", RFC 7172, May 2014.
[RFC7356] - Ginsberg, L., Previdi, S., and Y. Yang, "IS-IS Flooding
Scope Link State PDUs (LSPs)", RFC 7356, September 2014,
<http://www.rfc-editor.org/info/rfc7356>.
D. Eastlake and Y Li [Page 23]
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[RFC7357] - Zhai, H., Hu, F., Perlman, R., Eastlake 3rd, D., and O.
Stokes, "Transparent Interconnection of Lots of Links (TRILL):
End Station Address Distribution Information (ESADI) Protocol",
RFC 7357, September 2014, <http://www.rfc-
editor.org/info/rfc7357>.
[RFC7780] - Eastlake 3rd, D., Zhang, M., Perlman, R., Banerjee, A.,
Ghanwani, A., and S. Gupta, "Transparent Interconnection of
Lots of Links (TRILL): Clarifications, Corrections, and
Updates", RFC 7780, DOI 10.17487/RFC7780, February 2016,
<http://www.rfc-editor.org/info/rfc7780>.
Informational References
[ARPND] - Y. Li, S. Eastlake, L. Dunbar, R. Perlman, I. Gashinsky,
"TRILL: ARP/ND Optimization", draft-ietf-trill-arp-
optimization, work in progress.
[ChannelTunnel] - D. Eastlake, Y. Li, "TRILL: RBridge Channel Tunnel
Protocol", draft-eastlake-trill-channel-tunnel, work in
progress.
[DirectoryScheme] - Dunbar, L., D. Eastlake, R. Perlman, I.
Gashinsky, Y. Li, "TRILL": Directory Assistance Mechanisms",
draft-dunbar-trill-scheme-for-directory-assist, work in
progress.
[RFC5494] - Arkko, J. and C. Pignataro, "IANA Allocation Guidelines
for the Address Resolution Protocol (ARP)", RFC 5494, April
2009.
[RFC7067] - Dunbar, L., Eastlake 3rd, D., Perlman, R., and I.
Gashinsky, "Directory Assistance Problem and High-Level Design
Proposal", RFC 7067, November 2013.
[RFC7178] - Eastlake 3rd, D., Manral, V., Li, Y., Aldrin, S., and D.
Ward, "Transparent Interconnection of Lots of Links (TRILL):
RBridge Channel Support", RFC 7178, May 2014.
D. Eastlake and Y Li [Page 24]
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Authors' Addresses
Donald Eastlake
Huawei Technologies
155 Beaver Street
Milford, MA 01757 USA
Phone: +1-508-333-2270
Email: d3e3e3@gmail.com
Yizhou Li
Huawei Technologies
101 Software Avenue,
Nanjing 210012 China
Phone: +86-25-56622310
Email: liyizhou@huawei.com
D. Eastlake and Y Li [Page 25]
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D. Eastlake and Y Li [Page 26]
