Internet DRAFT - draft-ietf-rtgwg-srv6-egress-protection
draft-ietf-rtgwg-srv6-egress-protection
Network Working Group Z. Hu
Internet-Draft Huawei
Intended status: Standards Track H. Chen
Expires: 14 September 2023 Futurewei
H. Chen
China Telecom
P. Wu
Huawei
M. Toy
Verizon
C. Cao
T. He
China Unicom
L. Liu
Fujitsu
X. Liu
IBM Corporation
13 March 2023
SRv6 Path Egress Protection
draft-ietf-rtgwg-srv6-egress-protection-09
Abstract
This document describes protocol extensions for protecting the egress
node of a Segment Routing for IPv6 (SRv6) path or tunnel.
Requirements Language
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 RFC 2119 [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Hu, et al. Expires 14 September 2023 [Page 1]
Internet-Draft Egress Protection March 2023
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."
This Internet-Draft will expire on 14 September 2023.
Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminologies . . . . . . . . . . . . . . . . . . . . . . . . 3
3. SR Path Egress Protection . . . . . . . . . . . . . . . . . . 4
3.1. Mechanism . . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Example . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Extensions to IGP for Egress Protection . . . . . . . . . . . 9
4.1. Extensions to IS-IS . . . . . . . . . . . . . . . . . . . 9
4.2. Extensions to OSPF . . . . . . . . . . . . . . . . . . . 11
5. Security Considerations . . . . . . . . . . . . . . . . . . . 12
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
6.1. SRv6 Endpoint Behaviors . . . . . . . . . . . . . . . . . 12
6.2. IS-IS . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.3. OSPFv3 . . . . . . . . . . . . . . . . . . . . . . . . . 13
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. Normative References . . . . . . . . . . . . . . . . . . 13
7.2. Informative References . . . . . . . . . . . . . . . . . 14
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
Hu, et al. Expires 14 September 2023 [Page 2]
Internet-Draft Egress Protection March 2023
1. Introduction
The fast protection of a transit node of a Segment Routing (SR) path
or tunnel is described in [I-D.ietf-rtgwg-segment-routing-ti-lfa].
[RFC8400] specifies the fast protection of egress node(s) of an MPLS
TE LSP tunnel including P2P TE LSP tunnel and P2MP TE LSP tunnel in
details. However, these documents do not discuss the fast protection
of the egress node of a Segment Routing for IPv6 (SRv6) path or
tunnel.
This document fills that void and presents protocol extensions for
the fast protection of the egress node of an SRv6 path or tunnel.
Egress node and egress, fast protection and protection as well as
SRv6 path and SRv6 tunnel will be used exchangeably below.
There are a number of topics related to the egress protection, which
include the detection of egress node failure, the relation between
egress protection and global repair, and so on. These are discussed
in details in [RFC8679].
2. Terminologies
The following terminologies are used in this document.
SR: Segment Routing
SRv6: SR for IPv6
SRH: Segment Routing Header
SID: Segment Identifier
LSA: Link State Advertisement in OSPF
LSP: Label Switched Path in MPLS or Link State Protocol PDU in IS-IS
PDU: Protocol Data Unit
LS: Link Sate, which is LSA in OSPF or LSP in IS-IS
TE: Traffic Engineering
SA: Source Address
DA: Destination Address
P2MP: Point-to-MultiPoint
Hu, et al. Expires 14 September 2023 [Page 3]
Internet-Draft Egress Protection March 2023
P2P: Point-to-Point
CE: Customer Edge
PE: Provider Edge
LFA: Loop-Free Alternate
TI-LFA: Topology Independent LFA
BFD: Bidirectional Forwarding Detection
VPN: Virtual Private Network
L3VPN: Layer 3 VPN
VRF: Virtual Routing and Forwarding
FIB: Forwarding Information Base
PLR: Point of Local Repair
BGP: Border Gateway Protocol
IGP: Interior Gateway Protocol
OSPF: Open Shortest Path First
IS-IS: Intermediate System to Intermediate System
3. SR Path Egress Protection
This section describes the mechanism of SR path egress protection and
illustrates it through an example.
3.1. Mechanism
Figure 1 is used to explain the mechanism of SR path egress node
protection.
Hu, et al. Expires 14 September 2023 [Page 4]
Internet-Draft Egress Protection March 2023
******* ******* SIDa
[PE1]-----[P1]-----[PEA]---[CE2] PEA Egress
/ | |& | \ / PEB Backup Egress
/ | |& | \ / CEx Customer Edge
[CE1] | |& | X Px Non-Provider Edge
\ | |& | / \ *** SR Path
\ | |& &&&&& | / \ &&& Backup Path
[PE2]-----[P2]-----[PEB]---[CE3]
Mirror SID
Figure 1: PEB Protects Egress PEA of SR Path
Where node PEA is the egress of the SR path from PE1 to PEA, and has
SIDa which is the active segment in the packet from the SR path at
PEA. Node PEB is the backup egress (or say protector) to provide the
protection for egress (or say primary egress) PEA. Node P1 is the
direct previous/upstream hop of egress PEA and acts as PLR (refer to
[I-D.ietf-rtgwg-segment-routing-ti-lfa]) to support the protection
for PEA.
When PEB is selected as a backup egress to protect the egress PEA, a
Mirror SID (refer to Section 5.1 of [RFC8402]) is configured on PEB
to protect PEA. PEB advertises this information through IGP, which
includes the Mirror SID and the egress PEA. The information is
represented by <PEB, PEA, Mirror SID>, which indicates that PEB
protects PEA with Mirror SID.
After PEA receives the information <PEB, PEA, Mirror SID>, it may
send the forwarding behavior of the SIDa at PEA to PEB with the
Mirror SID using some protocols such as BGP if PEB can not obtain
this behavior from other approaches and PEB wants to protect SIDa of
PEA. How to send the forwarding behavior of the SIDa to PEB is out
scope of this document.
When PEB gets the forwarding behavior of the SIDa of PEA from PEA or
other means, it adds a forwarding entry for the SIDa according to the
behavior into the forwarding table for node PEA. This table is
identified by the Mirror SID, which indicates node PEA's context.
Using the forwarding entry for SIDa in this table, a packet with SIDa
will be transmitted by PEB to the same destination as it is
transmitted by PEA. For example, assume that the packet with SIDa is
transmitted by PEA to CE2 through the forwarding behavior of the SIDa
in PEA. The packet will be transmitted by PEB to the same CE2
through looking up the table identified by the Mirror SID.
Hu, et al. Expires 14 September 2023 [Page 5]
Internet-Draft Egress Protection March 2023
After P1 as PLR receives the information <PEB, PEA, Mirror SID> and
knows that PEB wants to protect SIDa of PEA, it computes an LFA for
PEA assuming that PEA and PEB have a same anycast address. A Repair
List RL is obtained based on the LFA. It is one of the followings:
o RL = <Mirror SID> if the LFA is the next hop node to PEB along the
shortest path to PEB; or
o RL = <S1, ..., Sn, Mirror SID> if the LFA is a TI-LFA, where <S1,
..., Sn> is the TI-LFA Repair List to PEB computed by P1.
When PEA fails, P1 as PLR sends the packet with SIDa carried by the
SR path to PEB, but encapsulates the packet before sending it by
executing H.Encaps with the Repair List RL and a Source Address T.
Suppose that the packet received by P1 is represented by Pkt = (S,
SIDa)Pkt0, where SA = S and DA = SIDa, and Pkt0 is the rest of the
packet.
The execution of H.Encaps pushes an IPv6 header to Pkt and sets some
fields in the outer and inner IPv6 header to produce an encapsulated
packet Pkt'. Pkt' will be one of the followings:
o Pkt' = (T, Mirror SID) (S, SIDa)Pkt0 if RL = <Mirror SID>; or
o Pkt' = (T, S1)(Mirror SID, Sn, ..., S1; SL=n) (S, SIDa)Pkt0 if RL
= <S1, ..., Sn, Mirror SID>.
When PEB receives the re-routed packet, which is (T, Mirror SID) (S,
SIDa)Pkt0, it decapsulates the packet and forwards the decapsulated
packet using the FIB table Tm identified by the Mirror SID as a
variant of End.DT6 SID. The Mirror SID is called End.M.
It obtains the Mirror SID in the outer IPv6 header of the packet,
removes this outer IPv6 header with all its extension headers, and
then processes the inner IPv6 packet (i.e., (S, SIDa)Pkt0, the packet
without the outer IPv6 header). PEB finds the FIB table Tm for node
PEA using the Mirror SID as the context ID, and submits the packet to
this FIB table lookup and transmission to the same destination as PEA
does.
The behavior of Mirror SID (End.M for short) is a variant of the
End.DT6 behavior (refer to Section 4.6 of [RFC8986]). The End.M SID
MUST be the last segment in an SR path, and a SID instance is
associated with an IPv6 FIB table Tm.
When processing the Upper-Layer header of a packet matching a FIB
entry locally instantiated as an End.M SID, N does the following:
Hu, et al. Expires 14 September 2023 [Page 6]
Internet-Draft Egress Protection March 2023
S01. If (Upper-Layer header type == 41(IPv6) ) {
S02. Remove the outer IPv6 header with all its extension headers
S03. Set the packet's associated FIB table to Tm
S04. Submit the packet to the egress IPv6 FIB lookup for
transmission to the new destination
S05. } Else {
S06. Process as per Section 4.1.1 of RFC8986
S07. }
3.2. Example
Figure 2 shows an example of protecting egress PE3 of a SR path,
which is from ingress PE1 to egress PE3.
Locator: A3:1::/64
******* ******* VPN SID: A3:1::B100
[PE1]-----[P1]-----[PE3]---[CE2] PE3 Egress
/ | |& | \ / PE4 Backup Egress
/ | |& | \ / CEx Customer Edge
[CE1] | |& | X Px Non-Provider Edge
\ | |& | / \ *** SR Path
\ | |& &&&&& | / \ &&& Backup Path
[PE2]-----[P2]-----[PE4]---[CE3]
Locator: A4:1::/64
VPN SID: A4:1::B100
Mirror SID: A4:1::3, protect A3:1::/64
Figure 2: PE4 Protects Egress PE3 of SR Path
Where node P1's pre-computed backup path for PE3 is from P1 to PE4
via P2. In normal operations, after receiving a packet with
destination PE3, P1 forwards the packet to PE3 according to its FIB.
When PE3 receives the packet, it sends the packet to CE2.
When PE3 fails, P1 as PLR detects the failure through using a failure
detection mechanism such as BFD and forwards the packet to PE4 via
the backup path. When PE4 receives the packet, it sends the packet
to the same CE2.
When P1's IGP converges on the failure of PE3, P1 as PLR needs to
retent the route to PE3 for a period of time. Thus the backup path
for PE3 will be used when the other nodes (such as PE1) still send
the packet to PE3 via P1 since their IGPs do not converge on the
failure.
Hu, et al. Expires 14 September 2023 [Page 7]
Internet-Draft Egress Protection March 2023
In Figure 2, Both CE2 and CE3 are dual home to PE3 and PE4. PE3 has
a locator A3:1::/64 and a VPN SID A3:1::B100. PE4 has a locator
A4:1::/64 and VPN SID A4:1::B100. A Mirror SID A4:1::3 is configured
on PE4 for protecting PE3 with locator A3:1::/64.
After the configuration, PE4 advertises this information through an
IGP LS (i.e., LSA in OSPF or LSP in IS-IS), which includes PE3's
locator and Mirror SID A4:1::3. Every node in the SR domain will
receive this IGP LS, which indicates that PE4 wants to protect PE3
(indicated by PE3's locator) with Mirror SID A4:1::3.
When PE4 (e.g., BGP on PE4) receives a prefix whose VPN SID belongs
to PE3 that is protected by PE4 through Mirror SID A4:1::3, it finds
PE4's VPN SID corresponding to PE3's VPN SID. For example, local PE4
has Prefix 1.1.1.1 with VPN SID A4:1::B100, when PE4 receives prefix
1.1.1.1 with remote PE3's VPN SID A3:1::B100, it knows that they are
for the same VPN.
The forwarding behaviors for these two VPN SIDs are the same from
function's point of view. If the behavior for PE3's VPN SID in PE3
forwards the packet with it to CE2, then the behavior for PE4's VPN
SID in PE4 forwards the packet to the same CE2; and vice versa. PE4
creates a forwarding entry for PE3's VPN SID A3:1::B100 in the FIB
table identified by Mirror SID A4:1::3 according to the forwarding
behavior for PE4's VPN SID A4:1::B100.
Node P1's pre-computed backup path for destination PE3 is from P1 to
PE4 having mirror SID A4:1::3. When P1 receives a packet destined to
PE3's VPN SID A3:1::B100, in normal operations, it forwards the
packet with source A1:1:: and destination PE3's VPN SID A3:1::B100
according to the FIB using the destination PE3's VPN SID A3:1::B100.
When PE3 fails, P1 as PLR sends the packet to PE4 via the backup path
pre-computed. P1 encapsulates the packet using H.Encaps before
sending it to PE4.
Suppose that the packet received by P1 is represented by Pkt = (SA =
A1:1::, DA = A3:1::B100)Pkt0, where DA = A3:1::B100 is PE3's VPN SID,
and Pkt0 is the rest of the packet. The encapsulated packet Pkt'
will be one of the followings:
o Pkt' = (T, Mirror SID A4:1::3) (A1:1::, A3:1::B100)Pkt0 if backup
path not via PE3; or (otherwise)
o Pkt' = (T, S1)(Mirror SID A4:1::3, Sn, ..., S1; SL=n) (A1:1::,
A3:1::B100)Pkt0.
Hu, et al. Expires 14 September 2023 [Page 8]
Internet-Draft Egress Protection March 2023
where T is a Source Address, <S1, ..., Sn> is the TI-LFA Repair List
to PE4 computed by P1 when the backup path to PE4 goes through PE3.
When PE4 receives the re-routed packet, it decapsulates the packet
and forwards the decapsulated packet by executing End.DT6 behavior
for an End.DT6 SID instance. The SID instance is End.M, the Mirror
SID that is associated with the IPv6 FIB table for PE3. The packet
received by PE4 is (T, Mirror SID A4:1::3) (A1:1::, PE3's VPN SID
A3:1::B100)Pkt0.
PE4 obtains Mirror SID A4:1::3 in the outer IPv6 header of the
packet, removes this outer IPv6 header, and then processes the inner
IPv6 packet (A1:1::, A3:1::B100)Pkt0. It finds the FIB table for PE3
using Mirror SID A4:1::3 as the context ID, gets the forwarding entry
for PE3's VPN SID A3:1::B100 from the table, and forwards the packet
to CE2 using the entry.
4. Extensions to IGP for Egress Protection
This section describes extensions to IS-IS and OSPF for advertising
the information about SRv6 path egress protection.
4.1. Extensions to IS-IS
A new sub-TLV, called IS-IS SRv6 Mirror SID sub-TLV, is defined. It
is used in the SRv6 Locator TLV defined in [RFC9352] to advertise
SRv6 Mirror SID and the locators of the nodes to be protected. The
SRv6 Mirror SID inherit the topology/algorithm from the parent
locator. The format of the sub-TLV is illustrated below.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (TBD1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | SRv6 Endpoint Function |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (16 octets) |
: :
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sub-sub-TLVs |
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: IS-IS SRv6 Mirror SID sub-TLV
Hu, et al. Expires 14 September 2023 [Page 9]
Internet-Draft Egress Protection March 2023
Type: TBD1 (suggested value 8) is to be assigned by IANA.
Length: variable.
Flags: 1 octet. No flags are currently defined.
SRv6 Endpoint Function: 2 octets. It contains the endpoint function
74 for Mirror SID.
SID: 16 octets. This field contains the SRv6 Mirror SID to be
advertised.
A protected locators sub-sub-TLV is defined and used to carry the
Locators of the egress nodes to be protected by the SRv6 mirror SID.
It has the following format.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (TBD2) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Locator-Size | Locator (variable) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Locator-Size | Locator (variable) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: IS-IS Protected Locators sub-sub-TLV
Type: TBD2 (suggested value 1) is to be assigned by IANA.
Length: variable.
Locator-Size: 1 octet. Number of bits (1 - 128) in the Locator
field.
Locator: 1-16 octets. This field encodes an SRv6 Locator of an
egress node to be protected by the SRv6 mirror SID. The Locator
is encoded in the minimal number of octets for the given number of
bits.
When node B advertises that B wants to protect node A with a Mirror
SID through an LSP, the LSP contains an IS-IS SRv6 Mirror SID sub-
TLV, which includes the Mirror SID and node A's locator in an IS-IS
Protected locators sub-sub-TLV.
Hu, et al. Expires 14 September 2023 [Page 10]
Internet-Draft Egress Protection March 2023
4.2. Extensions to OSPF
Similarly, a new sub-TLV, called OSPF Mirror SID sub-TLV, is defined.
It is used to advertise SRv6 Mirror SID and the locators of the nodes
to be protected. Its format is illustrated below.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (TBD4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Reserved | SRv6 Endpoint Function |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID (16 octets) |
: :
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sub-TLVs |
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: OSPF SRv6 Mirror SID sub-TLV
Type: TBD4 (suggested value 8) is to be assigned by IANA.
Length: variable.
Flags: 1 octet. No flags are currently defined.
Reserved: 1 octet. It MUST be set to zero for transmission and
ignored on reception.
SRv6 Endpoint Function: 2 octets. It contains the endpoint function
74 for End.M SID.
SID: 16 octets. This field contains the SRv6 Mirror SID to be
advertised.
A protected locators sub-TLV is defined and used to carry the
locators of the nodes to be protected by the SRv6 Mirror SID. It has
the following format.
Hu, et al. Expires 14 September 2023 [Page 11]
Internet-Draft Egress Protection March 2023
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (TBD5) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Locator-Size | Locator (variable) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Locator-Size | Locator (variable) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: OSPF Protected Locators sub-TLV
Type: TBD5 (suggested value 1) is to be assigned by IANA.
Length: variable.
Locator-Size: 1 octet. Number of bits (1 - 128) in the Locator
field.
Locator: 1-16 octets. This field encodes an SRv6 Locator of an
egress node to be protected by the SRv6 mirror SID. The Locator
is encoded in the minimal number of octets for the given number of
bits.
5. Security Considerations
The security about the egress protection is described in in details
in [RFC8679]. The extensions to OSPF and IS-IS described in this
document for SRv6 path egress protection should not cause extra
security issues.
6. IANA Considerations
6.1. SRv6 Endpoint Behaviors
Under sub-registry "SRv6 Endpoint Behaviors" [RFC8986], IANA has
assigned the following for End.M Endpoint Behavior:
+==============+========+=====================+===============+
| Value | Hex | Endpoint behavior | Reference |
+==============+========+=====================+===============+
| 74 | 0x004A | End.M (Mirror SID) | This document |
+--------------+--------+---------------------+---------------+
Hu, et al. Expires 14 September 2023 [Page 12]
Internet-Draft Egress Protection March 2023
6.2. IS-IS
Under "IS-IS Sub-TLVs for TLVs Advertising Prefix Reachability
registry", IANA is requested to add the following new Sub-TLV:
+==============+=========================+===============+
| Type | Description | Reference |
+==============+=========================+===============+
| 8 | SRv6 Mirror SID | This document |
+--------------+-------------------------+---------------+
IANA is requested to create and maintain a new registry for sub-sub-
TLVs of the SRv6 Mirror SID Sub-TLV. The suggested registry name is
o Sub-Sub-TLVs for SRv6 Mirror SID Sub-TLV
Initial values for the registry are given below. The future
assignments are to be made through IETF Review [RFC5226].
Value Sub-Sub-TLV Name Definition
----- ----------------------- -------------
0 Reserved
1 Protected Locators Sub-Sub-TLV This Document
2-255 Unassigned
6.3. OSPFv3
Under registry "OSPFv3 Locator LSA Sub-TLVs"
[I-D.ietf-lsr-ospfv3-srv6-extensions], IANA is requested to assign
the following new Sub-TLVs:
+==============+============================+===============+
| Sub-TLV Type | Sub-TLV Name | Reference |
+==============+============================+===============+
| 8 | SRv6 Mirror SID Sub-TLV | This document |
+--------------+----------------------------+---------------+
| 11 | Protected Locators Sub-TLV | This document |
+--------------+----------------------------+---------------+
7. References
7.1. Normative References
Hu, et al. Expires 14 September 2023 [Page 13]
Internet-Draft Egress Protection March 2023
[I-D.ietf-lsr-ospfv3-srv6-extensions]
Li, Z., Hu, Z., Talaulikar, K., and P. Psenak, "OSPFv3
Extensions for SRv6", Work in Progress, Internet-Draft,
draft-ietf-lsr-ospfv3-srv6-extensions-09, 14 January 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-lsr-
ospfv3-srv6-extensions-09>.
[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>.
[RFC8400] Chen, H., Liu, A., Saad, T., Xu, F., and L. Huang,
"Extensions to RSVP-TE for Label Switched Path (LSP)
Egress Protection", RFC 8400, DOI 10.17487/RFC8400, June
2018, <https://www.rfc-editor.org/info/rfc8400>.
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>.
[RFC8667] Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C.,
Bashandy, A., Gredler, H., and B. Decraene, "IS-IS
Extensions for Segment Routing", RFC 8667,
DOI 10.17487/RFC8667, December 2019,
<https://www.rfc-editor.org/info/rfc8667>.
[RFC8679] Shen, Y., Jeganathan, M., Decraene, B., Gredler, H.,
Michel, C., and H. Chen, "MPLS Egress Protection
Framework", RFC 8679, DOI 10.17487/RFC8679, December 2019,
<https://www.rfc-editor.org/info/rfc8679>.
[RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer,
D., Matsushima, S., and Z. Li, "Segment Routing over IPv6
(SRv6) Network Programming", RFC 8986,
DOI 10.17487/RFC8986, February 2021,
<https://www.rfc-editor.org/info/rfc8986>.
[RFC9352] Psenak, P., Ed., Filsfils, C., Bashandy, A., Decraene, B.,
and Z. Hu, "IS-IS Extensions to Support Segment Routing
over the IPv6 Data Plane", RFC 9352, DOI 10.17487/RFC9352,
February 2023, <https://www.rfc-editor.org/info/rfc9352>.
7.2. Informative References
Hu, et al. Expires 14 September 2023 [Page 14]
Internet-Draft Egress Protection March 2023
[I-D.ietf-rtgwg-segment-routing-ti-lfa]
Litkowski, S., Bashandy, A., Filsfils, C., Francois, P.,
Decraene, B., and D. Voyer, "Topology Independent Fast
Reroute using Segment Routing", Work in Progress,
Internet-Draft, draft-ietf-rtgwg-segment-routing-ti-lfa-
09, 23 December 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-rtgwg-
segment-routing-ti-lfa-09>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<https://www.rfc-editor.org/info/rfc5226>.
Acknowledgments
The authors would like to thank Acee Lindem, Peter Psenak, Yimin
Shen, Zhenqiang Li, Alexander Vainshtein, Greg Mirsky, Bruno
Decraene, Jeff Tantsura, Chris Bowers and Ketan Talaulikar for their
comments to this work.
Authors' Addresses
Zhibo Hu
Huawei
Huawei Bld., No.156 Beiqing Rd.
Beijing
100095
China
Email: huzhibo@huawei.com
Huaimo Chen
Futurewei
Boston, MA,
United States of America
Email: Huaimo.chen@futurewei.com
Huanan Chen
China Telecom
109, West Zhongshan Road, Tianhe District
Guangzhou
510000
China
Email: chenhn8.gd@chinatelecom.cn
Hu, et al. Expires 14 September 2023 [Page 15]
Internet-Draft Egress Protection March 2023
Peng Wu
Huawei
Huawei Bld., No.156 Beiqing Rd.
Beijing
100095
China
Email: baggio.wupeng@huawei.com
Mehmet Toy
Verizon
United States of America
Email: mehmet.toy@verizon.com
Chang Cao
China Unicom
Email: caoc15@chinaunicom.cn
Tao He
China Unicom
Email: het21@chinaunicom.cn
Lei Liu
Fujitsu
United States of America
Email: liulei.kddi@gmail.com
Xufeng Liu
IBM Corporation
United States of America
Email: xufeng.liu.ietf@gmail.com
Hu, et al. Expires 14 September 2023 [Page 16]
