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INTERNET-DRAFT W. Hao
Intended Status: Proposed Standard Huawei Technologies
D. Eastlake
Futurewei Technologies
J. Uttaro
AT&T
S. Litkowski
Cisco Systems
S. Zhuang
Huawei Technologies
Expires: June 30, 2020 December 31, 2019
BGP Dissemination of L2 Flow Specification Rules
draft-ietf-idr-flowspec-l2vpn-13
Abstract
This document defines a Border Gateway Protocol (BGP) Flow-spec
extension to disseminate Ethernet Layer 2 (L2) and Layer 2 Virtual
Private Network (L2VPN) traffic filtering rules either by themselves
or in conjunction with L3 Flow-specs. AFI/SAFI 6/133 and 25/134 are
used for these purposes. New component types and an extended
community also are defined.
Status of This Document
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Distribution of this document is unlimited. Comments should be sent
to the authors or the IDR Working Group mailing list <idr@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.
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.
W. Hao, et al [Page 1]
INTERNET-DRAFT L2 Flow Spec
Table of Contents
1. Introduction............................................3
1.1 Terminology............................................4
2. Layer 2 Flow Specification Encoding.....................5
2.1 L2 Component Types.....................................6
2.1.1 Type 1 - Ethernet Type (EtherType)...................6
2.1.2 Type 2 - Source MAC..................................7
2.1.3 Type 3 - Destination MAC.............................7
2.1.4 Type 4 - DSAP (Destination Service Access Point).....7
2.1.5 Type 5 - SSAP (Source Service Access Point)..........7
2.1.6 Type 6 - Control field in LLC........................7
2.1.7 Type 7 - SNAP........................................8
2.1.8 Type 8 - VLAN ID.....................................8
2.1.9 Type 9 - VLAN PCP....................................8
2.1.10 Type 10 - Inner VLAN ID.............................8
2.1.11 Type 11 - Inner VLAN PCP............................9
2.1.12 Type 12 - VLAN DEI..................................9
2.1.13 Type 13 - Inner VLAN DEI............................9
2.1.14 Type 14 - Source MAC Special Bits...................9
2.1.15 Type 15 - Destination MAC Special Bits.............10
2.2 Order of L2 Traffic Filtering Rules...................10
3. L2VPN Flow Specification Encoding in BGP...............12
3.1 Order of L2VPN Filtering Rules........................12
4. Ethernet Flow Specification Traffic Actions............13
4.1 VLAN-action...........................................13
4.2 TPID-action...........................................15
5. Flow Spec Validation...................................16
6. IANA Considerations....................................17
7. Security Considerations................................18
8. Acknowledgements.......................................18
9. Contributors...........................................18
Normative References......................................19
Informative References....................................20
W. Hao, et al [Page 2]
INTERNET-DRAFT L2 Flow Spec
1. Introduction
Border Gateway Protocol (BGP) Flow-spec [RFC5575bis] is an extension
to BGP that supports the dissemination of traffic flow specification
rules and actions to be taken on packets in a specified flow. It
leverages the BGP Control Plane to simplify the distribution of ACLs
(Access Control Lists). Using the Flow-spec extension new filter
rules can be injected to all BGP peers simultaneously without
changing router configuration. A typical application is to automate
the distribution of traffic filter lists to routers for DDoS
(Distributed Denial of Service) mitigation, access control, and
similar applications.
BGP Flow-spec [RFC5575bis] defines a BGP Network Layer Reachability
Information (NLRI) format used to distribute traffic flow
specification rules. NLRI (AFI=1, SAFI=133) is for IPv4 unicast
filtering. NLRI (AFI=1, SAFI=134) is for IPv4 BGP/MPLS VPN filtering
[RFC7432]. The Flow specification match part defined in [RFC5575bis]
only includes L3/L4 information like IPv4 source/destination prefix,
protocol, ports, and the like, so traffic flows can only be filtered
based on L3/L4 information. This has been extended by [FlowSpecV6]
which covers IPv6 (AFI=2) L3/L4.
Layer 2 Virtual Private Networks (L2VPNs) have been deployed in an
increasing number of networks. Such networks also have requirements
to deploy BGP Flow-spec to mitigate DDoS attack traffic. Within an
L2VPN network, both IP and non-IP Ethernet traffic maybe exist. For
IP traffic filtering, the VPN Flow specification rules defined in
[RFC5575bis] and/or [FlowSpecV6], which include match criteria and
actions, can still be used. Flow specification rules received via the
new NLRI format apply only to traffic that belongs to the VPN
instance(s) in which it is imported. For non-IP Ethernet traffic
filtering, Layer 2 related information like source/destination MAC
and VLAN must be considered.
There are different kinds of L2VPN networks like EVPN [RFC7432], BGP
VPLS [RFC4761], LDP VPLS [RFC4762] and border gateway protocol (BGP)
auto discovery [RFC6074]. Because the Flow-spec feature relies on
the BGP protocol to distribute traffic filtering rules, it can only
be incrementally deployed in those L2VPN networks where BGP has
already been used for auto discovery and/or signaling purposes such
as BGP-based VPLS [RFC4761], EVPN and LDP-based VPLS [RFC4762] with
BGP auto-discovery [RFC6074].
This draft defines new Flow-spec component types and two new extended
communities to support L2 and L2VPN Flow-spec applications. The
Flow-spec rules can be enforced on all border routers or on some
interface sets of the border routers. SAFI=133 in [RFC5575bis] and
[FlowSpecV6] is extended for AFI=6 as specified in Section 2 to cover
L2 traffic filtering information and in Section 3 SAFI=134 is
W. Hao, et al [Page 3]
INTERNET-DRAFT L2 Flow Spec
extended for AFI=25 to cover the L2VPN environment.
1.1 Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
The following acronyms are used in this document:
AFI - Address Family Identifier
ACL - Access Control List
DDoS - Distributed Denial of Service
EVPN - Ethernet VPN [RFC7432]
L2 - Layer 2
L2VPN - Layer 2 VPN
L3 - Layer 3
L3VPN - Layer 3 VPN
NLRI - Network Layer Reachability Information
PCP - Priority Code Point [802.1Q]
SAFI - Subsequent Address Family Identifier
TPID - Tag Protocol ID, typically a VLAN ID
VLAN - Virtual Local Area Network
VPLS - Virtual Private Line Service [RFC4762]
VPN - Virtual Private Network
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INTERNET-DRAFT L2 Flow Spec
2. Layer 2 Flow Specification Encoding
[RFC5575bis] defines SAFI 133 and SAFI 134, with AFI=1, for
"dissemination of IPv4 flow specification rules" and "dissemination
of VPNv4 flow specification rules", respectively. [FlowSpecV6]]
extends [RFC5575bis] to also allow AFI=2 thus making it applicable to
both IPv4 and IPv6 applications. This document further extends
SAFI=133 for AFI=6 and SAFI=134 for AFI=25 to make them applicable to
L2 and L2VPN applications. This document also provides for the
optional inclusion of L3 flow specifications with the L2 flow
specifications.
This section specifies the L2 Flow Spec for AFI=6/SAFI=133. (SAFI=133
is updated by the [FlowSpecV6] draft so as to not be restricted to
the Layer of the AFI with which it operates.) To simplify
assignments, a new registry is used for L2 Flow-spec. Since it is
frequently desirable to also filter on L3/L4 fields, provision is
made for their inclusion along with an indication of the L3 protocol
involved (IPv4 or IPv6).
The NLRI part of the MP_REACH_NLRI and MP_UNREACH_NLRI is encoded as
a 1- or 2-octet total NLRI length field followed by several fields as
described below.
+-------------------------------+
| total-length (0xnn or 0xfnnn) | 2 or 3 octets
+-------------------------------+
| L3-AFI | 2 octets
+-------------------------------+
| L2-length (0xnn or 0xfnnn) | 2 or 3 octets
+-------------------------------+
| NLRI-value | variable
+-------------------------------+
Figure 1: Flow Specification NLRI for L2
The fields show in Figure 1 are further specified below:
total-length: The length of the subsequent fields (L3 AFI,
L2-length, and NRLI-vaue) encoded as provided in Section 4.1 of
[RFC5575bis]. If this field is less than 4, which is the
minimum valid value, then the NLRI is malformed in which case a
NOTIFICATION message is sent and the BGP connection closed as
provided in Section 6.3 of [RFC4271].
L3-AFI: If no L3/L4 filtering is desired, this two octet field
MUST be zero. Otherwise it indicates the L3 protocol involved
by giving its AFI (0x0001 for IPv4 or 0x0002 for IPv6). If the
receiver does not understand the value of this field, the
MP_REACH or MP_UNREACH attribute is ignored.
W. Hao, et al [Page 5]
INTERNET-DRAFT L2 Flow Spec
L2-length: The length of the L2 components at the beginning of the
NLRI-value field encoded as provided in Section 4.1 of
[RFC5575bis]. If the value of this field indicates that the L2
components extend beyond the total-length, the NLRI is
malformed in which case a NOTIFICATION message is sent and the
BGP connection closed as provided in Section 6.3 of [RFC4271].
N2-length MAY be zero although, in that case, it would have
been more efficient to encode the attribute as an L3 Flow spec
unless it is desired to apply an L2 action (see Section 4). A
null L2 Flow-spec always matches.
NLRI-value: This consists of the L2 Flow Spec, of length
L2-length, followed by an optionally present L3 Flow. The
result can be treated in most ways as a single Flow spec,
matching the intersection (AND) of all the components except
that the components in the initial L2 region are interpreted as
L2 components and the remainder as L3 components per the L3-AFI
field. This is necessary because there are different registries
for the L2, L3 IPv4, and L3 IPv6 component types. If the L3
Flow-spec is null (length zero), it always matches.
2.1 L2 Component Types
The L2 Flow-spec portion of NLRI-value consists of Flow-spec
components as in [RFC5575bis] but using L2 components and types as
specified below. All components start with a type octet followed by a
length octet followed by any additional information needed. The
length octet give the length, in octets, of the information after the
length octet. This structure applies to all new components to be
defined in the L2 Flow-spec Component Registry (see Section 6) and to
all existing components except Types 2 and 3 where the length is in
bits.
2.1.1 Type 1 - Ethernet Type (EtherType)
Encoding: <type (1 octet), length (1 octet), [op, value]+>
Defines a list of {operation, value} pairs used to match the two-
octet EtherType field. op is encoded as specified in Section 4.2.1.1
of [RFC5575bis]. Values are encoded as 2-octet quantities. Ethernet
II framing defines the two-octet Ethernet Type (EtherType) field in
an Ethernet frame, preceded by destination and source MAC addresses,
that identifies an upper layer protocol encapsulating the frame data.
W. Hao, et al [Page 6]
INTERNET-DRAFT L2 Flow Spec
2.1.2 Type 2 - Source MAC
Encoding: <type (1 octet), MAC Prefix length (1 octet), MAC Prefix>
Defines the source MAC Address prefix to match encoded as in BGP
UPDATE messages [RFC4271]. Prefix length is in bits and the MAC
Prefix is fill out with unused bit to an integer number of octets.
2.1.3 Type 3 - Destination MAC
Encoding: <type (1 octet), MAC Prefix length (1 octet), MAC Prefix>
Defines the destination MAC Address to match encoded as in BGP UPDATE
messages [RFC4271]. Prefix length is in bits and the MAC Prefix is
fill out with unused bit to an integer number of octets.
2.1.4 Type 4 - DSAP (Destination Service Access Point)
Encoding: <type (1 octet), length (1 octet), [op, value]+>
Defines a list of {operation, value} pairs used to match the 1-octet
DSAP in the IEEE 802.2 LLC (Logical Link Control Header). Values are
encoded as 1-octet quantities. op is encoded as specified in Section
4.2.1.1 of [RFC5575bis].
2.1.5 Type 5 - SSAP (Source Service Access Point)
Encoding: <type (1 octet), length (1 octet), [op, value]+>
Defines a list of {operation, value} pairs used to match the 1-octet
SSAP in the IEEE 802.2 LLC. Values are encoded as 1-octet
quantities. op is encoded as specified in Section 4.2.1.1 of
[RFC5575bis].
2.1.6 Type 6 - Control field in LLC
Encoding: <type (1 octet), length (1 octet), [op, value]+>
Defines a list of {operation, value} pairs used to match 1-octet
control field in the IEEE 802.2 LLC. Values are encoded as 1-octet
quantities. op is encoded as specified in Section 4.2.1.1 of
[RFC5575bis].
W. Hao, et al [Page 7]
INTERNET-DRAFT L2 Flow Spec
2.1.7 Type 7 - SNAP
Encoding: <type (1 octet), length (1 octet), [op, value]+>
Defines a list of {operation, value} pairs used to match 5-octet SNAP
(Sub-Network Access Protocol) field. Values are encoded as 5-octet
quantities. op is encoded as specified in Section 4.2.1.1 of
[RFC5575bis].
2.1.8 Type 8 - VLAN ID
Encoding: <type (1 octet), length (1 octet), [op, value]+>
Defines a list of {operation, value} pairs used to match VLAN ID.
Values are encoded as 2-octet quantities, where the four most
significant bits are zero and the 12 least significant bits contain
the VLAN value. op is encoded as specified in Section 4.2.1.1 of
[RFC5575bis].
In the virtual local-area network (VLAN) stacking case, the VLAN ID
is the outer VLAN ID.
2.1.9 Type 9 - VLAN PCP
Encoding: <type (1 octet), length (1 octet), [op, value]+>
Defines a list of {operation, value} pairs used to match 3-bit VLAN
PCP fields [802.1Q]. Values are encoded using a single octet, where
the five most significant bits are zero and the three least
significant bits contain the VLAN PCP value. op is encoded as
specified in Section 4.2.1.1 of [RFC5575bis].
In the virtual local-area network (VLAN) stacking case, the VLAN PCP
is outer VLAN PCP.
2.1.10 Type 10 - Inner VLAN ID
Encoding: <type (1 octet), length (1 octet), [op, value]+>
Defines a list of {operation, value} pairs used to match the inner
VLAN ID using for virtual local-area network (VLAN) stacking or Q-in-
Q use. Values are encoded as 2-octet quantities, where the four most
significant bits are zero and the 12 least significant bits contain
the VLAN value. op is encoded as specified in Section 4.2.1.1 of
W. Hao, et al [Page 8]
INTERNET-DRAFT L2 Flow Spec
[RFC5575bis].
In the single VLAN case, this component type MUST NOT be used. If it
appears the match will fail.
2.1.11 Type 11 - Inner VLAN PCP
Encoding: <type (1 octet), length (1 octet), [op, value]+>
Defines a list of {operation, value} pairs used to match 3-bit inner
VLAN PCP fields [802.1Q] using for virtual local-area network (VLAN)
stacking or Q in Q use. Values are encoded using a single octet,
where the five most significant bits are zero and the three least
significant bits contain the VLAN PCP value. op is encoded as
specified in Section 4.2.1.1 of [RFC5575bis].
In the single VLAN case, this component type MUST NOT be used. If it
appears the match will fail.
2.1.12 Type 12 - VLAN DEI
Encoding: <type (1 octet), length (1 octet), op (1 octet)>
This type tests the DEI bit in the VLAN tag. If op is zero, it
matches if and only if the DEI bit is zero. If op is non-zero, it
matches if and only if the DEI bit is one.
2.1.13 Type 13 - Inner VLAN DEI
Encoding: <type (1 octet), length (1 octet), op (1 octet)>
This type tests the DEI bit in the inner VLAN tag. If op is zero, it
matches if and only if the DEI bit is zero. If op is non-zero, it
matches if and only if the DEI bit is one.
In the single VLAN case, this component type MUST NOT be used. If it
appears the match will fail.
2.1.14 Type 14 - Source MAC Special Bits
Encoding: <type (1 octet), length (1 octet), op (1 octet)>
W. Hao, et al [Page 9]
INTERNET-DRAFT L2 Flow Spec
This type tests the bottom nibble of the top octet of the Source MAC
address. The two low order bits of that nibble have long been the
local bit (0x2) and the group addressed bit (0x1). However, recent
changes in IEEE 802 have divided the local address space into 4
quadrants specified by the next two bits (0x4 and 0x8) [RFC7042bis].
This type permits testing, for example, that a MAC is group addressed
or is a local address in a particular quadrant. The encoding is as
given in Section 4.2.1.2 of [RFC5575bis].
2.1.15 Type 15 - Destination MAC Special Bits
Encoding: <type (1 octet), length (1 octet), op (1 octet)>
As discussed in Section 2.1.14 but for the Destination MAC Address.
2.2 Order of L2 Traffic Filtering Rules
L2 Flow-specs take precedence over L3 Flow-specs. Between two L2
Flow-specs, precedence is determined as specified in this section
after this paragraph. If the L2 Flow-specs are the same, then the L3
Flow-specs are compared as specified in [RFC5575bis or [FlowSpecV6]
as appropriate. Note: if the L3-AFI fields are different between two
L2 Flow-specs, they will never match the same packet so it will not
be necessary to prioritize two Flow-specs with different L3-AFI
values.
The original definition for the order of traffic filtering rules can
be reused for L2 with new consideration for the MAC Address offset.
As long as the offsets are equal, the comparison is the same,
retaining longest-prefix-match semantics. If the offsets are not
equal, the lowest offset has precedence, as this flow matches the
most significant bit.
W. Hao, et al [Page 10]
INTERNET-DRAFT L2 Flow Spec
Pseudocode:
flow_rule_L2_cmp (a, b)
{
comp1 = next_component(a);
comp2 = next_component(b);
while (comp1 || comp2) {
// component_type returns infinity on end-of-list
if (component_type(comp1) < component_type(comp2)) {
return A_HAS_PRECEDENCE;
}
if (component_type(comp1) > component_type(comp2)) {
return B_HAS_PRECEDENCE;
}
if (component_type(comp1) == MAC_DESTINATION || MAC_SOURCE) {
common = MIN(MAC Address length (comp1),
MAC Address length (comp2));
cmp = MAC Address compare(comp1, comp2, common);
// not equal, lowest value has precedence
// equal, longest match has precedence
} else {
common =
MIN(component_length(comp1), component_length(comp2));
cmp = memcmp(data(comp1), data(comp2), common);
// not equal, lowest value has precedence
// equal, longest string has precedence
}
}
return EQUAL;
}
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INTERNET-DRAFT L2 Flow Spec
3. L2VPN Flow Specification Encoding in BGP
The NLRI format for AFI=25/SAFI=134 (L2VPN), as with the other VPN
Flow-spec AFI/SAFI pairs, is the same as the non-VPN Flow-Spec but
with the addition of a Route Distinguisher to identify the VPN to
which the Flow-spec is to be applied.
In addition, the IANA entry for SAFI 134 is slightly generalized as
specified at the beginning of Section 6.
The NLRI format is as follows:
+-------------------------------+
| total-length (0xnn or 0xfnnn) | 2 or 3 octets
+-------------------------------+
| Route Distinguisher | 8 octets
+-------------------------------+
| L3-AFI | 2 octets
+-------------------------------+
| L2-length (0xnn or 0xfnnn) | 2 or 3 octets
+-------------------------------+
| NLRI-value | variable
+-------------------------------+
Figure 2: Flow Specification NLRI for L2VPN
The fields in Figure 2, other than the Route Distinguisher, are
encoded as specified in Section 2 except that the minimum value for
total-length is 12.
Flow specification rules received via this NLRI apply only to traffic
that belongs to the VPN instance(s) into which it is imported. Flow
rules are accepted as specified in Section 5.
3.1 Order of L2VPN Filtering Rules
The order between L2VPN filtering rules is determined as specified in
Section 2.2. Note that if the Route Distinguisher is different
between two L2VPN filtering rules, they will never both match the
same packet so they need not be prioritized.
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INTERNET-DRAFT L2 Flow Spec
4. Ethernet Flow Specification Traffic Actions
The default action for a layer 2 traffic filtering flow specification
is to accept traffic that matches that particular rule. The
following extended community values per [RFC5575bis] can be used to
specify particular actions in an L2 VPN network:
+--------+--------------------+----------------------------+
| type | extended community | encoding |
+--------+--------------------+----------------------------+
| 0x8006 | traffic-rate | 2-octet as#, 4-octet float |
| 0x8007 | traffic-action | bitmask |
| 0x8008 | redirect | 6-octet Route Target |
| 0x8009 | traffic-marking | DSCP value |
+--------+--------------------+----------------------------+
Redirect: The action should be redefined to allow the traffic to be
redirected to a MAC or IP VRF routing instance that lists the
specified route-target in its import policy.
Besides the above extended communities, this document also specifies
the following BGP extended communities for Ethernet flows to extend
[RFC5575bis]:
+--------+------------------------+--------------------------+
| type | extended community | encoding |
+--------+------------------------+--------------------------+
| TBD1 | VLAN-action | bitmask |
| TBD2 | TPID-action | bitmask |
+--------+------------------------+--------------------------+
4.1 VLAN-action
The VLAN-action extended community, as shown in the diagram below,
consists of 6 octets that include action Flags, two VLAN IDs, and the
associated PCP and DEI values. The action Flags fields are further
divided into two parts which correspond to the first action and the
second action respectively. Bit 0 to bit 7 give the first action
while bit 8 to bit 15 give the second action. The bits of PO, PU,
SW, RI and RO in each part represent the action of Pop, Push, Swap,
Rewrite inner VLAN and Rewrite outer VLAN respectively. Through this
method, more complicated actions also can be represented in a single
VLAN-action extended community, such as SwapPop, PushSwap, etc. For
example, SwapPop action is the sequence of two actions, the first
action is Swap and the second action is Pop.
W. Hao, et al [Page 13]
INTERNET-DRAFT L2 Flow Spec
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|PO1|PU1|SW1|RI1|RO1| Resv |PO2|PU2|SW2|RI2|RO2| Resv |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
| VLAN ID1 |PCP1 |DE1|
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
| VLAN ID2 |PCP2 |DE2|
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
PO1: Pop action. If the PO1 flag is one, it indicates the outmost
VLAN should be removed.
PU1: Push action. If PU1 is one, it indicates VLAN ID1 will be
added, the associated PCP and DEI are PCP1 and DE1.
SW1: Swap action. If the SW1 flag is one, it indicates the outer
VLAN and inner VLAN should be swapped.
PO2: Pop action. If the PO2 flag is one, it indicates the outmost
VLAN should be removed.
PU2: Push action. If PU2 is one, it indicates VLAN ID2 will be
added, the associated PCP and DEI are PCP2 and DE2.
SW2: Swap action. If the SW2 flag is one, it indicates the outer
VLAN and inner VLAN should be swapped.
RI1 and RI2: Rewrite inner VLAN action. If the RI flag is one, it
indicates the inner VLAN should be replaced by a new VLAN where the
new VLAN is VLAN ID1 and the associated PCP and DEO are PCP1 and DE1.
If the VLAN ID1 is 0, the action is to only modify the PCP and DEI
value of the inner VLAN.
RO1 and RO2: Rewrite outer VLAN action. If the RO flag is one, it
indicates the outer VLAN should be replaced by a new VLAN where the
new VLAN is VLAN ID and the associated PCP and DEI are PCP2 and DE2.
If the VLAN ID2 is 0, the action is to only modify the PCP and DEI
value of the outer VLAN.
Resv, R1, and R2: Reserved for future use. MUST be sent as zero and
ignored on receipt.
Giving an example below: if the action of PUSH Inner VLAN 10 with PCP
value 5 DEI value 0 and Outer VLAN 20 with PCP value 6 DEI value 0 is
needed, the format of the VLAN-action extended community is as
follows:
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INTERNET-DRAFT L2 Flow Spec
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|0 |1 |0 |0 |0 |0 |0 |0 |0 |1 |0 |0 |0 |0 |0 |0 |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| 10 |1 |0 |1 |0 |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| 20 |1 |1 |0 |0 |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
4.2 TPID-action
The TPID-action extended community consists of 6 octets which
includes the fields of action Flags, TPID1 and TPID2.
0 15
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|TI|TO| Resv |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| TP ID1 |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| TP ID2 |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
TI: Mapping inner TP ID action. If the TI flag is one, it indicates
the inner TP ID should be replaced by a new TP ID, the new TP ID is
TP ID1.
TO: Mapping outer TP ID action. If the TO flag is one, it indicates
the outer TP ID should be replaced by a new TP ID, the new TP ID is
TP ID2.
Resv: Reserved for future use. MUST be sent as zero and ignored on
receipt.
W. Hao, et al [Page 15]
INTERNET-DRAFT L2 Flow Spec
5. Flow Spec Validation
Flow-specs received over AFI=25/SAFI=134 are validated against
routing reachability received over AFI=25/SAFI=128 as modified to
conform to [FlowSpecOID].
W. Hao, et al [Page 16]
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6. IANA Considerations
IANA is requested to change the description for SAFI 134 [RFC5575bis]
to read as follows and to change the reference for it to [this
document]:
134 VPN dissemination of flow specification rules
IANA is requested to create an L2 Flow Spec Component Type registry
on the Flow Spec Component Types registries web page as follows:
Name: L2 Flow Spec Component Types
Reference: [this document]
Registration Procedures:
0 Reserved
1-127 Specification Required
128-255 First Come First Served
Initial contents:
+------+-----------------------+------------------------------+
| type | Reference | description |
+------+-----------------------+------------------------------+
| 0 | [this document] | Reserved |
| 1 | [this document] | Ethernet Type |
| 2 | [this document] | Source MAC |
| 3 | [this document] | Destination MAC |
| 4 | [this document] | DSAP in LLC |
| 5 | [this document] | SSAP in LLC |
| 6 | [this document] | Control field in LLC |
| 7 | [this document] | SNAP |
| 8 | [this document] | VLAN ID |
| 9 | [this document] | VLAN PCP |
| 10 | [this document] | Inner VLAN ID |
| 11 | [this document] | Inner VLAN PCP |
| 12 | [this document] | VLAN DEI |
| 13 | [this document] | Inner VLAN DEI |
| 14 | [this document] | Source MAC Special Bits |
| 15 | [this document] | Destination MAC Special Bits|
|16-254| [this document] | unassigned |
| 255 | [this document] | reserved |
+------+-----------------------+------------------------------+
IANA is requested to assign two values from the "BGP Extended
Communities Type - extended, transitive" registry [suggested value
provided in square brackets]:
Type value Name Reference
------------ ------------------------ ---------------
TBD1[0x080A] Flow spec VLAN action [this document]
TBD2[0x080B] Flow spec TPID action [this document]
W. Hao, et al [Page 17]
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7. Security Considerations
For General BGP Flow-spec Security Considerations, see [RFC5575bis].
VLAN tagging identifies Layer 2 communities which are commonly
expected to be isolated except when higher layer connection is
provided, such as Layer 3 routing. The ability of the Flow-spec VLAN
action to change the VLAN ID in a frame may thus compromise security.
8. Acknowledgements
The authors wish to acknowledge the important contributions and
suggestions of the following:
Hannes Gredler, Xiaohu Xu, Zhenbin Li, Lucy Yong, and Feng Dong.
9. Contributors
Qiandeng Liang
Huawei Technologies
101 Software Avenue, Yuhuatai District
Nanjing 210012
China
Email: liangqiandeng@huawei.com
W. Hao, et al [Page 18]
INTERNET-DRAFT L2 Flow Spec
Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI
10.17487/RFC2119, March 1997, <https://www.rfc-
editor.org/info/rfc2119>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A Border
Gateway Protocol 4 (BGP-4)", RFC 4271, DOI
10.17487/RFC4271, January 2006, <https://www.rfc-
editor.org/info/rfc4271>.
[RFC4761] Kompella, K., Ed. and Y. Rekhter, Ed., "Virtual Private LAN
Service (VPLS) Using BGP for Auto-Discovery and Signaling",
RFC 4761, DOI 10.17487/RFC4761, January 2007,
<https://www.rfc-editor.org/info/rfc4761>.
[RFC4762] Lasserre, M., Ed. and V. Kompella, Ed., "Virtual Private
LAN Service (VPLS) Using Label Distribution Protocol (LDP)
Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007,
<https://www.rfc-editor.org/info/rfc4762>.
[RFC6074] Rosen, E., Davie, B., Radoaca, V., and W. Luo,
"Provisioning, Auto-Discovery, and Signaling in Layer 2
Virtual Private Networks (L2VPNs)", RFC 6074, DOI
10.17487/RFC6074, January 2011, <https://www.rfc-
editor.org/info/rfc6074>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119
Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May
2017, <https://www.rfc-editor.org/info/rfc8174>.
[FlowSpecOID] Uttaro, J., Alcaide, J., Filsfils, C. Smith, D.,
Mohapatra, P., draft-ietf-idr-bgp-flowspec-oid, work in
progress.
[FlowSpecV6] McPherson, D., Raszuk, R., Pithawala, B.,
akarch@cisco.com, a., and S. Hares, "Dissemination of Flow
Specification Rules for IPv6", draft-ietf-idr-flow-spec-
v6-10. Work in progress.
[RFC5575bis] Hares, S., Loibl, C., Raszuk, R., McPherson, D., Bacher,
M., "Dissemination of Flow Specification Rules", draft-
ietf-idr-rfc5575bis-18, Work in progress.
W. Hao, et al [Page 19]
INTERNET-DRAFT L2 Flow Spec
Informative References
[RFC7432] Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based
Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February
2015, <https://www.rfc-editor.org/info/rfc7432>.
[RFC7042bis] Eastlake, D., and J. Abley, "IANA Considerations and
IETF Protocol and Documentation Usage for IEEE 802
Parameters", draft-eastlake-rfc7042bis, Work in progress.
W. Hao, et al [Page 20]
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Authors' Addresses
Weiguo Hao
Huawei Technologies
101 Software Avenue,
Nanjing 210012
China
Email: haoweiguo@huawei.com
Donald E. Eastlake, 3rd
Futurewei Technologies
2386 Panoramic Circle
Apopka, FL 32703
USA
Tel: +1-508-333-2270
Email: d3e3e3@gmail.com
James Uttaro
AT&T
Email: uttaro@att.com
Stephane Litkowski
Cisco Systems, Inc.
Email: slitkows.ietf@gmail.com
Shunwan Zhuang
Huawei Technologies
Huawei Bld., No.156 Beiqing Rd.
Beijing 100095
China
Email: zhuangshunwan@huawei.com
W. Hao, et al [Page 21]
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W. Hao, et al [Page 22]
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