IS-IS TLV Codepoints

Created
2003-05-06
Last Updated
2021-12-02
Note
For IS-IS registries and value ranges maintained via the "Expert 
Review" [RFC8126] registration procedure, guidance for IESG-designated 
experts can be found in [RFC7370].
  
Available Formats

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HTML

Plain text

Registries included below

IS-IS Top-Level TLV Codepoints

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
Top-level TLVs for the IS-IS protocol
Reference
[RFC3563][RFC6233][RFC7356][RFC8918]
Note
IETF SHALL keep JTC1/SC6 informed of TLV codepoint values allocated, 
and JTC1/SC6 SHALL refer allocation requests arising within JTC1 
constituencies to the IANA registry process.
    
Note
Codepoints greater than 255 can only be used in PDUs designated to 
support extended TLVs.
    
Available Formats

CSV
Value Name IIH LSP SNP Purge Status/Reference
0 Reserved
1 Area Addresses y y n n [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
2 IIS Neighbors n y n n [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
3 ES Neighbors n y n n [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
4 Part. DIS n y n n [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
5 Prefix Neighbors n y n n [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
6 IIS Neighbors y n n n [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
7 Instance Identifier y y y y [RFC8202]
8 Padding y n n n [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
9 LSP Entries n n y n [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
10 Authentication y y y y [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.][RFC6233]
11 ESN TLV y n y n [RFC7602]
12 Opt. Checksum y n y n [RFC3358]
13 Purge Originator Identification n n n y [RFC8918]
14 LSPBufferSize n y n n [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
15 Router-Fingerprint y y n y [RFC8196]
16 Reverse Metric y n n n [RFC8500]
17 IS-IS Area Node IDs TLV (TEMPORARY - registered 2019-08-08, extension registered 2021-06-18, expires 2022-08-08) n y n n [draft-ietf-lsr-dynamic-flooding]
18 IS-IS Flooding Path TLV (TEMPORARY - registered 2019-08-08, extension registered 2021-06-18, expires 2022-08-08) n y n n [draft-ietf-lsr-dynamic-flooding]
19 IS-IS Flooding Request TLV (TEMPORARY - registered 2019-08-08, extension registered 2021-06-18, expires 2022-08-08) y n n n [draft-ietf-lsr-dynamic-flooding]
20 Area Proxy (TEMPORARY - registered 2020-08-31, extension registered 2021-07-27, expires 2022-08-31) n y n n [draft-ietf-lsr-isis-area-proxy-06]
21 Unassigned
22 Extended IS reachability n y n n [RFC5305]
23 IS Neighbor Attribute n y n n [RFC5311]
24 IS Alias ID n y n n [RFC5311]
25 L2 Bundle Member Attributes n y n n [RFC8668]
26 Unassigned
27 SRv6 Locator n y n n [RFC-ietf-lsr-isis-srv6-extensions-18]
28 Zone ID (TEMPORARY - registered 2020-11-20, extension registered 2021-10-28, expires 2022-11-20) n y n n [draft-ietf-lsr-isis-ttz-01]
29-41 Unassigned
42 DECnet Phase IV y n n n DEC (ancient)
43-65 Unassigned
66 Lucent Proprietary n y n n
67-125 Unassigned
126 IPv4 Algorithm Prefix Reachability TLV (TEMPORARY - registered 2021-04-27, expires 2022-04-27) n y n n [draft-ietf-lsr-ip-flexalgo-01]
127 IPv6 Algorithm Prefix Reachability TLV (TEMPORARY - registered 2021-04-27, expires 2022-04-27) n y n n [draft-ietf-lsr-ip-flexalgo-01]
128 IP Int. Reach n y n n [RFC1195][RFC5302]
129 Prot. Supported y y n n [RFC1195]
130 IP Ext. Address n y n n [RFC1195][RFC5302]
131 IDRPI n y y n [RFC1195]
132 IP Intf. Address y y n n [RFC1195]
133 Illegal n n n n [RFC1195] (not used)
134 Traffic Engineering router ID n y n n [RFC5305]
135 Extended IP reachability n y n n [RFC5305]
136 Unassigned
137 Dynamic Name n y n y [RFC5301] [RFC6233]
138 GMPLS-SRLG n y n n [RFC5307]
139 IPv6 SRLG n y n n [RFC6119]
140 IPv6 TE Router ID n y n n [RFC6119]
141 inter-AS reachability information n y n n [RFC5316]
142 GADDR-TLV n y n n [RFC7176]
143 MT-Port-Cap-TLV y n n n [RFC6165]
144 MT-Capability TLV n y n n [RFC6329]
145 TRILL Neighbor TLV y n n n [RFC7176]
146 Unassigned
147 MAC-RI TLV n y n n [RFC6165]
148 BFD-Enabled TLV y n n n [RFC6213]
149 Segment Identifier / Label Binding n y n n [RFC8667]
150 Multi-Topology Segment Identifier / Label Binding n y n n [RFC8667]
151-160 Unassigned
161 Flood Reflection (TEMPORARY - registered 2020-08-05, extension registered 2021-06-18, expires 2022-08-05) y n n n [draft-ietf-lsr-isis-flood-reflection-01]
162-175 Unassigned
176 Nortel Proprietary n y n n
177 Nortel Proprietary n y n n
178-210 Unassigned
211 Restart TLV y n n n [RFC8706]
212-221 Unassigned
222 MT-ISN n y n n [RFC5120]
223 MT IS Neighbor Attribute n y n n [RFC5311]
224-228 Unassigned
229 M-Topologies y y n n [RFC5120]
230-231 Unassigned
232 IPv6 Intf. Addr. y y n n [RFC5308]
233 IPv6 Global Interface Address TLV y n n n [RFC6119]
234 Unassigned
235 MT IP. Reach n y n n [RFC5120]
236 IPv6 IP. Reach n y n n [RFC5308]
237 MT IPv6 IP. Reach n y n n [RFC5120]
238 Application-Specific SRLG n y n n [RFC8919]
239 Unassigned
240 P2P 3-Way Adj. State y n n n [RFC5303]
241 Unassigned
242 IS-IS Router CAPABILITY TLV n y n n [RFC7981]
243 Scope Flooding Support y n n n [RFC7356]
244-250 Unassigned
251 Generic Information n y n n [RFC6823]
252-65535 Unassigned

IS-IS Authentication Type Codes

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
Type Codes for Authentication TLV (10)
Reference
[RFC5304]
Available Formats

CSV
Value Authentication Type Code Reference
0 Reserved [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
1 Cleartext Password [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
2 ISO 10589 Reserved [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]
3 Cryptographic Authentication (CRYPTO_AUTH) [RFC5310]
4-53 Unassigned
54 HMAC-MD5 Authentication [RFC5304]
55-254 Unassigned
255 Routing Domain private authentication method [ISO 10589, "Intermediate System to Intermediate System Intra- Domain Routeing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", International Standard 10589: 2002, Second Edition, 2002.]

IS-IS Sub-TLVs for Reverse Metric TLV

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
Sub-TLVs for Reverse Metric TLV (16)
Reference
[RFC8500]
Available Formats

CSV
Type Description Reference
0 Reserved [RFC8500]
1-17 Unassigned
18 Traffic Engineering Metric [RFC8500, Section 2]
19-255 Unassigned

IS-IS Sub-TLVs for TLVs Advertising Neighbor Information

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
This registry defines sub-TLVs for TLVs advertising neighbor information. 
The list of TLVs includes:
 
Extended IS reachability (22)
IS Neighbor Attribute (23)
L2 Bundle Member Attributes (25)
inter-AS reachability information (141)
MT-ISN (222)
MT IS Neighbor Attribute (223)
Reference
[RFC5305][RFC5316][RFC7370][RFC8668]
Note
Allocations within this registry require documentation of the use of 
the allocated value and approval by the Designated Expert assigned by 
the IESG.
    
Note
The column for TLV 25 may be marked as follows:
      
y - sub-TLV may appear in TLV 25 but MUST NOT be shared by multiple L2 Bundle Members
y(s) - sub-TLV may appear in TLV 25 and MAY be shared by multiple L2 Bundle Members
n - sub-TLV MUST NOT appear in TLV 25
    
Available Formats

CSV
Type Description 22 23 25 141 222 223 Reference
0-2 Unassigned
3 Administrative group (color) y y y(s) y y y [RFC5305]
4 Link Local/Remote Identifiers y y y(s) y y y [RFC5307]
5 Unassigned
6 IPv4 interface address y y y(s) y y y [RFC5305]
7 Unassigned
8 IPv4 neighbor address y y y(s) y y y [RFC5305]
9 Maximum link bandwidth y y y(s) y y y [RFC5305]
10 Maximum reservable link bandwidth y y y(s) y y y [RFC5305]
11 Unreserved bandwidth y y y(s) y y y [RFC5305]
12 IPv6 Interface Address y y y(s) y y y [RFC6119]
13 IPv6 Neighbor Address y y y(s) y y y [RFC6119]
14 Extended Administrative Group y y y(s) y y y [RFC7308]
15 Link MSD y y y y y y [RFC8491]
16 Application-Specific Link Attributes y y y(s) y y y [RFC8919]
17 Unassigned
18 TE Default metric y y y(s) y y y [RFC5305]
19 Link-attributes y y y(s) y y y [RFC5029]
20 Link Protection Type y y y(s) y y y [RFC5307]
21 Interface Switching Capability Descriptor y y y(s) y y y [RFC5307]
22 Bandwidth Constraints y y y(s) y y y [RFC4124]
23 Unconstrained TE LSP Count (sub-)TLV y y y(s) y y y [RFC5330]
24 remote AS number n n n y n n [RFC5316]
25 IPv4 remote ASBR Identifier n n n y n n [RFC5316]
26 IPv6 remote ASBR Identifier n n n y n n [RFC5316]
27 Interface Adjustment Capability Descriptor (IACD) y y y(s) y y y [RFC6001]
28 MTU y y n n y y [RFC7176]
29 SPB-Metric y y y(s) n y y [RFC6329]
30 SPB-A-OALG y y y(s) n y y [RFC6329]
31 Adjacency Segment Identifier y y n y y y [RFC8667]
32 LAN Adjacency Segment Identifier y y n y y y [RFC8667]
33 Unidirectional Link Delay y y y y y y [RFC8570]
34 Min/Max Unidirectional Link Delay y y y y y y [RFC8570]
35 Unidirectional Delay Variation y y y y y y [RFC8570]
36 Unidirectional Link Loss y y y y y y [RFC8570]
37 Unidirectional Residual Bandwidth y y y y y y [RFC8570]
38 Unidirectional Available Bandwidth y y y y y y [RFC8570]
39 Unidirectional Utilized Bandwidth y y y y y y [RFC8570]
40 RTM Capability y y n n y y [RFC8169]
41 L2 Bundle Member Adj-SID n n y n n n [RFC8668]
42 L2 Bundle Member LAN Adj-SID n n y n n n [RFC8668]
43 SRv6 End.X SID y y y y y y [RFC-ietf-lsr-isis-srv6-extensions-18, Section 8.1]
44 SRv6 LAN End.X SID y y y y y y [RFC-ietf-lsr-isis-srv6-extensions-18, Section 8.2]
45-160 Unassigned
161 Flood Reflector Adjacency (TEMPORARY - registered 2020-08-05, extension registered 2021-06-18, expires 2022-08-05) y y n y y y [draft-ietf-lsr-isis-flood-reflection-01]
162-249 Unassigned
250-254 Reserved for Cisco-specific extensions
255 Reserved for future expansion

IS-IS Neighbor Link-Attribute Bit Values

Registration Procedure(s)
Standards Action
Description
This registry defines bit values for the Link-attributes sub-TLV (19) 
advertised in TLVs advertising neighbor information. These TLVs are 
listed in the description of the “IS-IS Sub-TLVs for TLVs Advertising 
Neighbor Information” registry.
Reference
[RFC5029]
Available Formats

CSV
Value Name Reference
0x1 Local Protection Available [RFC5029]
0x2 Link Excluded from Local Protection [RFC5029]
0x4 Local Edge Enabled for Flooding (LEEF) (TEMPORARY - registered 2019-08-08, extension registered 2021-06-18, expires 2022-08-08) [draft-ietf-lsr-dynamic-flooding]

IS-IS Sub-TLVs for TLVs Advertising Prefix Reachability

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
This registry defines sub-TLVs for TLVs advertising prefix reachability. 
The list of TLVs includes:

SRv6 Locator (27)
Extended IP reachability (135)
MT IP Reach (235)
IPv6 IP Reach (236)
MT IPv6 IP Reach (237)
Reference
[RFC5305][RFC7370][RFC-ietf-lsr-isis-srv6-extensions-18]
Note
Allocations within this registry require documentation of the use of 
the allocated value and approval by the Designated Expert assigned by 
the IESG.
    
Available Formats

CSV
Type Description 27 135 235 236 237 Reference
0 Unassigned
1 32-bit Administrative Tag Sub-TLV y y y y y [RFC5130]
2 64-bit Administrative Tag Sub-TLV y y y y y [RFC5130]
3 Prefix Segment Identifier n y y y y [RFC8667]
4 Prefix Attribute Flags y y y y y [RFC7794]
5 SRv6 End SID y n n n n [RFC-ietf-lsr-isis-srv6-extensions-18, Section 7.2]
6 Flex-Algorithm Prefix Metric (TEMPORARY - registered 2019-10-02, extension registered 2021-08-16, expires 2022-10-02) n y y y y [draft-ietf-lsr-flex-algo]
7-10 Unassigned
11 IPv4 Source Router ID y y y y y [RFC7794]
12 IPv6 Source Router ID y y y y y [RFC7794]
13-31 Unassigned
32 BIER Info n y y y y [RFC8401]
33-255 Unassigned

IS-IS Bit Values for Prefix Attribute Flags Sub-TLV

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
This registry defines bit values for the Prefix Attribute Flags (4) 
sub-TLV advertised in Prefix Reachability TLVs. These TLVs are listed 
in the description of the "IS-IS Sub-TLVs for TLVs Advertising Prefix 
Reachability” registry.
Reference
[RFC7794]
Available Formats

CSV
Bit # Name Reference
0 External Prefix Flag (X-flag) [RFC7794]
1 Re-advertisement Flag (R-flag) [RFC7794]
2 Node Flag (N-flag) [RFC7794]
3 ELC Flag (E-flag) [RFC9088]
4 Anycast Flag (A-flag) [RFC-ietf-lsr-isis-srv6-extensions-18, Section 6]

IS-IS Group Address Type Codes for GADDR-TLV

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
This registry defines Group Address Type Codes for the GADDR-TLV (142).
Reference
[RFC7176]
Available Formats

CSV
Type Description Reference
0 Reserved [RFC7176]
1 GMAC-ADDR [RFC7176]
2 GIP-ADDR [RFC7176]
3 GIPV6-ADDR [RFC7176]
4 GLMAC-ADDR [RFC7176]
5 GLIP-ADDR [RFC7176]
6 GLIPV6-ADDR [RFC7176]
7-254 Unassigned
255 Reserved [RFC7176]

IS-IS Sub-TLVs for MT-Port-Cap-TLV

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
This registry defines sub-TLVs for the MT-Port-Cap-TLV (143).
Reference
[RFC7176]
Available Formats

CSV
Value Group Address Type Code Reference
0 Reserved [RFC7176]
1 VLAN-FLAGs [RFC7176]
2 Enabled-VLANs [RFC7176]
3 AppointedFwrdrs [RFC7176]
4 SPB-MCID [RFC6329]
5 SPB-Digest [RFC6329]
6 SPB-B-VID [RFC6329]
7 PORT-TRILL-VER [RFC7176]
8 VLANs-Appointed [RFC7176]
9-254 Unassigned
255 Reserved [RFC7176]

IS-IS Sub-TLVs for MT-Capability TLV

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
This registry defines sub-TLVs for the MT-Capability TLV (144).
Reference
[RFC6329]
Available Formats

CSV
Value Group Address Type Code Reference
0 Reserved [RFC6329]
1 SPB-Inst [RFC6329]
2 SPB-I-OALG [RFC6329]
3 SPBM-SI [RFC6329]
4 SPBV-ADDR [RFC6329]
5 Unassigned
6 NICKNAME [RFC7176]
7 TREES [RFC7176]
8 TREE-RT-IDs [RFC7176]
9 TREE-USE-IDs [RFC7176]
10 INT-VLAN [RFC7176]
11-12 Unassigned
13 TRILL-VER [RFC7176]
14 VLAN-GROUP [RFC7176]
15 INT-LABEL [RFC7176]
16 RBCHANNELS [RFC7176]
17 AFFINITY [RFC7176]
18 LABEL-GROUP [RFC7176]
19-20 Unassigned
21 Topology sub-TLV [RFC7813]
22 Hop sub-TLV [RFC7813]
23 Bandwidth Constraint sub-TLV [RFC7813]
24 Bandwidth Assignment sub-TLV [RFC7813]
25 Timestamp sub-TLV [RFC7813]
26-254 Unassigned
255 Reserved [RFC6329]

IS-IS Sub-TLVs for IS-IS Router CAPABILITY TLV

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
This registry defines sub-TLVs for the IS-IS Router CAPABILITY TLV (242).
Reference
[RFC7981]
Note
Allocations within this registry require documentation of the use of 
the allocated value and approval by the Designated Expert assigned by 
the IESG.
    
Available Formats

CSV
Value Description Reference
0 Reserved
1 TE Node Capability Descriptor [RFC5073]
2 Segment Routing Capability [RFC8667]
3 TE-MESH-GROUP TLV (IPv4) [RFC4972]
4 TE-MESH-GROUP TLV (IPv6) [RFC4972]
5 PCED sub-TLV [RFC5089]
6 NICKNAME [RFC7176]
7 TREES [RFC7176]
8 TREE-RT-IDs [RFC7176]
9 TREE-USE-IDs [RFC7176]
10 INT-VLAN [RFC7176]
11 IPv4 TE Router ID [RFC5316]
12 IPv6 TE Router ID [RFC5316]
13 TRILL-VER [RFC7176]
14 VLAN-GROUP [RFC7176]
15 INT-LABEL [RFC7176]
16 RBCHANNELS [RFC7176]
17 AFFINITY [RFC7176]
18 LABEL-GROUP [RFC7176]
19 Segment Routing Algorithm [RFC8667]
20 S-BFD Discriminators [RFC7883]
21 Node-Admin-Tag [RFC7917]
22 Segment Routing Local Block (SRLB) [RFC8667]
23 Node MSD [RFC8491]
24 Segment Routing Mapping Server Preference (SRMS Preference) [RFC8667]
25 SRv6 Capabilities [RFC-ietf-lsr-isis-srv6-extensions-18, Section 2]
26 Flexible Algorithm Definition (TEMPORARY - registered 2018-06-04, extension registered 2021-06-01, expires 2022-06-04) [draft-ietf-lsr-flex-algo-16]
27 IS-IS Area Leader Sub-TLV (TEMPORARY - registered 2019-08-08, extension registered 2021-06-18, expires 2022-08-08) [draft-ietf-lsr-dynamic-flooding]
28 IS-IS Dynamic Flooding Sub-TLV (TEMPORARY - registered 2019-08-08, extension registered 2021-06-18, expires 2022-08-08) [draft-ietf-lsr-dynamic-flooding]
29 IP Algorithm Sub-TLV (TEMPORARY - registered 2021-04-27, expires 2022-04-27) [draft-ietf-lsr-ip-flexalgo-01]
30-160 Unassigned
161 Flood Reflection Discovery (TEMPORARY - registered 2020-08-05, extension registered 2021-06-18, expires 2022-08-05) [draft-ietf-lsr-isis-flood-reflection-01]
162-255 Unassigned

IS-IS Sub-Sub-TLVs for SRv6 Capability Sub-TLV

Registration Procedure(s)
Expert Review
Expert(s)
Unassigned
Description
This registry defines sub-sub-TLVs for the SRv6 Capability Sub-TLV (25) 
advertised in the IS-IS Router Capabilities TLV (242).
Reference
[RFC-ietf-lsr-isis-srv6-extensions-18]
Available Formats

CSV
Value Description Reference
0 Reserved [RFC-ietf-lsr-isis-srv6-extensions-18]
1-255 Unassigned

IS-IS SRv6 Capabilities Sub-TLV Flags

Registration Procedure(s)
Expert Review
Expert(s)
Unassigned
Description
This registry defines bit values advertised in the flags field of the 
SRv6 Capabilities sub-TLV (25). This sub-TLV is advertised in the 
IS-IS Router CAPABILITY TLV (242).
Reference
[RFC-ietf-lsr-isis-srv6-extensions-18]
Available Formats

CSV
Type Description Reference
0 Unassigned
1 O-flag [RFC-ietf-lsr-isis-srv6-extensions-18, Section 2]
2-15 Unassigned

IS-IS Application Identifiers for Generic Information TLV

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
This registry defines Application Identifiers for the Generic Information 
TLV (251).
Reference
[RFC6823]
Available Formats

CSV
ID Value Description Allowed in Instance zero (y/n) Reference
0 Reserved [RFC6823]
1 TRILL n [RFC7357]
2-65535 Unassigned

IS-IS Sub-Sub-TLVs for BIER Info Sub-TLV

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Les Ginsberg
Description
This registry defines sub-sub-TLV codes which may be advertised in the 
BIER Info sub-TLV, which is advertised in Prefix Reachability TLVs. 
These TLVs are listed in the description of the "IS-IS Sub-TLVs for 
TLVs Advertising Prefix Reachability” registry.
Reference
[RFC8401]
Available Formats

CSV
Type Name Reference
0 Unassigned
1 BIER MPLS Encapsulation [RFC8401]
2-255 Unassigned

IS-IS Sub-TLVs for Segment Identifier/Label Binding TLVs

Registration Procedure(s)
Expert Review
Expert(s)
Chris Hopps, Hannes Gredler, Les Ginsberg
Description
This registry defines sub-TLVs for Segment Identifier/Label Binding 
TLVs. The list of TLVs includes:
 
Segment Identifier/Label Binding (149)
Multi-Topology Segment Identifier/Label Binding (150)
Reference
[RFC8667]
Available Formats

CSV
Type Description Reference
0 Reserved [RFC8667]
1 SID/Label [RFC8667]
2 Unassigned
3 Prefix Segment Identifier [RFC8667]
4-255 Unassigned

IS-IS Sub-Sub-TLV Codepoints for Application-Specific Link Attributes

Registration Procedure(s)
Expert Review
Expert(s)
Les Ginsberg, Chris Hopps
Description
This registry defines sub-sub-TLV codepoints for the Application-Specific 
Link Attributes sub-TLV, which is advertised in TLVs advertising 
neighbor information. These TLVs are listed in the description of the 
“IS-IS Sub-TLVs for TLVs Advertising Neighbor Information” registry.
Reference
[RFC8919]
Note
For future codepoints, in cases where the document that defines 
the encoding is different from the document that assigns the 
codepoint, the encoding reference MUST be to the document that 
defines the encoding.
    
Note
If a link attribute can be advertised both as a sub-TLV of TLVs 
advertising neighbor information and as a sub-sub-TLV of the 
Application-Specific Link Attributes sub-TLV defined in [RFC8919], 
then the same numerical code should be assigned to the link attribute 
whenever possible.
    
Available Formats

CSV

IS-IS Sub-TLVs for Application-Specific SRLG TLV

Registration Procedure(s)
Expert Review
Expert(s)
Les Ginsberg, Chris Hopps
Description
This registry defines sub-TLVs for Application Specific SRLG TLV (238).
Reference
[RFC8919]
Note
For future codepoints, in cases where the document that defines the 
encoding is different from the document that assigns the codepoint, 
the encoding reference MUST be to the document that defines the
encoding.
    
Available Formats

CSV
Value Description Reference
0-3 Unassigned
4 Link Local/Remote Identifiers [RFC5307]
5 Unassigned
6 IPv4 interface address [RFC5305]
7 Unassigned
8 IPv4 neighbor address [RFC5305]
9-11 Unassigned
12 IPv6 Interface Address [RFC6119]
13 IPv6 Neighbor Address [RFC6119]
14-255 Unassigned

IS-IS Sub-Sub-TLVs for SRv6 SID Sub-TLVs

Registration Procedure(s)
Expert Review
Expert(s)
Unassigned
Description
This registry defines Sub-Sub-TLVs for SRv6 SID Sub-TLVs. This includes 
the following sub-TLVs:
  
SRv6 End SID (5) (Advertised in SRv6 Locator TLV (27))
SRv6 End.X SID (43) (Advertised in TLVs advertising neighbor information)
SRv6 LAN End.X SID (44) (Advertised in TLVs advertising neighbor information)
Reference
[RFC-ietf-lsr-isis-srv6-extensions-18]
Available Formats

CSV
Type Description 5 43 44 Reference
0 Reserved [RFC-ietf-lsr-isis-srv6-extensions-18]
1 SRv6 SID Structure y y y [RFC-ietf-lsr-isis-srv6-extensions-18]
2-255 Unassigned

IS-IS SRv6 Locator TLV Flags

Registration Procedure(s)
Expert Review
Expert(s)
Unassigned
Description
This registry defines bit values advertised in the flags field of the 
SRv6 Locator TLV (27).
Reference
[RFC-ietf-lsr-isis-srv6-extensions-18]
Available Formats

CSV
Value Description Reference
0 D-flag [RFC-ietf-lsr-isis-srv6-extensions-18, Section 7.1]
1-7 Unassigned

IS-IS SRv6 End SID Sub-TLV Flags

Registration Procedure(s)
Expert Review
Expert(s)
Unassigned
Description
This registry defines bit values advertised in the flags field of the 
SRv6 End SID sub-TLV (5), which is advertised in the SRv6 Locator TLV 
(27).
Reference
[RFC-ietf-lsr-isis-srv6-extensions-18]
Available Formats

CSV
Value Description Reference
0-7 Unassigned

IS-IS SRv6 Adjacency SID Sub-TLVs Flags

Registration Procedure(s)
Expert Review
Expert(s)
Unassigned
Description
This registry defines bit values advertised in the flags field of 
SRv6 SID sub-TLVs associated with adjacencies. These sub-TLVs are 
advertised in TLVs advertising neighbor information. The list of 
sub-TLVs includes:

SRv6 End.X SID (43)
SRv6 LAN End.X SID (44)
Reference
[RFC-ietf-lsr-isis-srv6-extensions-18]
Available Formats

CSV
Value Description Reference
0 B-flag [RFC-ietf-lsr-isis-srv6-extensions-18, Section 8.1]
1 S-flag [RFC-ietf-lsr-isis-srv6-extensions-18, Section 8.1]
2 P-flag [RFC-ietf-lsr-isis-srv6-extensions-18, Section 8.1]
3-7 Unassigned