draft-ietf-idr-bgp-ls-node-admin-tag-extension-01.txt   draft-ietf-idr-bgp-ls-node-admin-tag-extension-02.txt 
Inter-Domain Routing P. Sarkar, Ed. Inter-Domain Routing P. Sarkar, Ed.
Internet-Draft Arrcus, Inc. Internet-Draft Arrcus, Inc.
Intended status: Standards Track H. Gredler Intended status: Standards Track H. Gredler
Expires: December 6, 2017 RtBrick, Inc. Expires: January 26, 2018 RtBrick, Inc.
S. Litkowski S. Litkowski
Orange Orange
June 04, 2017 July 25, 2017
Advertising Node Admin Tags in BGP Link-State Advertisements Advertising Node Admin Tags in BGP Link-State Advertisements
draft-ietf-idr-bgp-ls-node-admin-tag-extension-01 draft-ietf-idr-bgp-ls-node-admin-tag-extension-02
Abstract Abstract
This document describes the protocol extensions to collect node This document describes the protocol extensions to collect node
administrative tags adevertised in IGP Link State advertisements and administrative tags adevertised in IGP Link State advertisements and
disseminate the same in BGP Link-State advertisement protocol, to disseminate the same in BGP Link-State advertisement protocol, to
facilitate inter-AS TE applications that may need the same node facilitate inter-AS TE applications that may need the same node
administrative tags to associate a subset of network devices spanning administrative tags to associate a subset of network devices spanning
across more than one AS with a specific functionality. across more than one AS with a specific functionality.
skipping to change at page 1, line 44 skipping to change at page 1, line 44
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This Internet-Draft will expire on December 6, 2017. This Internet-Draft will expire on January 26, 2018.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Per-Node Administrative Tag . . . . . . . . . . . . . . . . . 4 2. Per-Node Administrative Tag . . . . . . . . . . . . . . . . . 3
3. BGP-LS Extensions for Per-Node Administrative Tags . . . . . 5 3. BGP-LS Extensions for Per-Node Administrative Tags . . . . . 4
3.1. Node Admin Tag TLV . . . . . . . . . . . . . . . . . . . 5 3.1. Node Admin Tag TLV . . . . . . . . . . . . . . . . . . . 5
4. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 7 4. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 7
5. Applications . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Applications . . . . . . . . . . . . . . . . . . . . . . . . 8
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
7. Manageability Considerations . . . . . . . . . . . . . . . . 9 7. Manageability Considerations . . . . . . . . . . . . . . . . 9
7.1. Operational Considerations . . . . . . . . . . . . . . . 9 7.1. Operational Considerations . . . . . . . . . . . . . . . 9
7.1.1. Operations . . . . . . . . . . . . . . . . . . . . . 9 7.1.1. Operations . . . . . . . . . . . . . . . . . . . . . 9
8. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . . . 9 8. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . . . 9
9. Security Considerations . . . . . . . . . . . . . . . . . . . 9 9. Security Considerations . . . . . . . . . . . . . . . . . . . 9
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
11.1. Normative References . . . . . . . . . . . . . . . . . . 9 11.1. Normative References . . . . . . . . . . . . . . . . . . 9
11.2. Informative References . . . . . . . . . . . . . . . . . 10 11.2. Informative References . . . . . . . . . . . . . . . . . 10
11.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 10 11.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction 1. Introduction
Advertising Node Administrative Tags in Link State protocols like IS- Advertising Node Administrative Tags in Link State protocols like IS-
IS [RFC7917] and OSPF [RFC7777] allows adding an optional operational IS [RFC7917] and OSPF [RFC7777] defines an optional operational
capability, that allows tagging and grouping of the nodes in a IGP capability, that allows tagging and grouping of the nodes in a IGP
domain. This, among other applications, allows simple management and domain. This, among other applications, allows simple management and
easy control over route and path selection, based on local configured easy control over route and path selection, based on local configured
policies. However node administrative tags advertised in IGP policies. However, node administrative tags advertised in IGP
advertisements let network operators associate nodes within a single advertisements let network operators associate nodes within a single
AS (if not a single area). This limits the use of such node AS (if not a single area). This limits the use of such node
administrative tags and applications that need to associate a subset administrative tags and applications that need to associate a subset
of network devices spanning across multiple AS with a specific of network devices spanning across multiple AS with a specific
functionality cannot use them. functionality cannot use them.
To address the need for applications that require visibility into To address the need for applications that require visibility into
LSDB across IGP areas, or even across ASes, the BGP-LS address- Link State Databases (LSDBs) across IGP areas, or even across ASes,
family/sub-address-family have been defined that allows BGP to carry the BGP-LS address-family/sub-address-family have been defined that
LSDB information. The BGP Network Layer Reachability Information allows BGP to carry LSDB information. The BGP Network Layer
(NLRI) encoding format for BGP-LS and a new BGP Path Attribute called Reachability Information (NLRI) encoding format for BGP-LS and a new
BGP-LS attribute are defined in [RFC7752]. The identifying key of BGP Path Attribute called BGP-LS attribute are defined in [RFC7752].
each LSDB object, namely a node, a link or a prefix, is encoded in Please refer to [RFC7752] for more details.
the NLRI and the properties of the object are encoded in the BGP-LS
attribute. Figure 1 describes a typical deployment scenario. In
each IGP area, one or more nodes are configured with BGP-LS. These
BGP speakers form an IBGP mesh by connecting to one or more route-
reflectors. This way, all BGP speakers - specifically the route-
reflectors - obtain LSDB information from all IGP areas (and from
other ASes from EBGP peers). An external component connects to the
route-reflector to obtain this information (perhaps moderated by a
policy regarding what information is sent to the external component,
and what information isn't).
+------------+
| Consumer |
+------------+
^
|
v
+-------------------+
| BGP Speaker | +-----------+
| (Route-Reflector) | | Consumer |
+-------------------+ +-----------+
^ ^ ^ ^
| | | |
+---------------+ | +-------------------+ |
| | | |
v v v v
+-----------+ +-----------+ +-----------+
| BGP | | BGP | | BGP |
| Speaker | | Speaker | . . . | Speaker |
+-----------+ +-----------+ +-----------+
^ ^ ^
| | |
IGP IGP IGP
Figure 1: Link State info collection
For the purpose of advertising node administrative tags within BGP For the purpose of advertising node administrative tags within BGP
Link-State advertisements, a new Node Attribute TLV to be carried in Link-State advertisements, a new Node Attribute TLV to be carried in
the corresponding BGP-LS Node NLRI is proposed. For more details on the corresponding BGP-LS Node NLRI is proposed. For more details on
the Node Attribute TLVs please refer to section 3.3.1 in [RFC7752] the Node Attribute TLVs please refer to section 3.3.1 in [RFC7752]
2. Per-Node Administrative Tag 2. Per-Node Administrative Tag
An administrative Tag is a 32-bit integer value that can be used to An administrative Tag is a 32-bit integer value that can be used to
identify a group of nodes in the entire routing domain. The new sub- identify a group of nodes in the entire routing domain. The new TLV
TLV specifies one or more administrative tag values. A BGP Link- and sub-TLV proposed in IS-IS [RFC7917] and OSPF [RFC7777]
State speaker that also participates in the IGP link state respectively, specifies one or more administrative tag values. A BGP
Link-State speaker that also participates in the IGP link state
advertisements exchange may learn one or more node administrative advertisements exchange may learn one or more node administrative
tags advertised by another router in the same IGP domain. Such BGP- tags advertised by another router in the same IGP domain. Such BGP-
LS speaker shall encode the same set of node administrative tags in LS speaker shall encode the same set of node administrative tags in
the corresponding Node Attribute TLV representing the network device the corresponding Node Attribute TLV representing the network device
that originated the node administrative tags. that originated the node administrative tags.
The node administrative tags advertised in IGP link state The node administrative tags advertised in IGP link state
advertisements will have either per-area(or levels in IS-IS)scope or advertisements will have either per-area(or per-level in IS-IS)scope
'global' scope. Operator may choose to a set of node administrative or 'global' scope. An operator may choose to advertise one set of
tags across areas (or levels in IS-IS) and another advertise set of node administrative tags across areas (or levels in IS-IS) and
node administrative tags within the specific area (or level). But advertise another set of node administrative tags within a specific
evidently two areas within the same AS or two different may use the area (or level). But evidently two areas within the same AS or two
same node administrative tag for different purposes. In such case different AS's may use the same node administrative tag for different
applications will need to distinguish between the per-area(or level) purposes. In such a case, applications will need to distinguish
scoped administrative tags originated from a specific node against between the per-area(or per-level) scoped administrative tags
those originated from the same node with 'global' scope. originated from a specific node against those originated from the
same node with 'global' scope.
A BGP-LS router in a given AS while copying the node administrative A BGP-LS router in a given AS while copying the node administrative
tags learnt from IGP link-state advertisements, MUST also copy the tags learnt from IGP link-state advertisements, MUST also copy the
scope associated with the node administrative tags. Refer to scope associated with the node administrative tags. Refer to
Section 3.1 for how to encode the associated scope of a node Section 3.1 for how to encode the associated scope of a node
administrative tags as well. administrative tags as well.
To be able to distinguish between the significance of a per-area(or To be able to distinguish between the significance of an
level) administrative tag learnt in one area, from that advertised in administrative tag learnt in one area, from that advertised in
another area, or another AS, any applications receiving such a BGP-LS another area, or another AS, any applications receiving such a BGP-LS
advertisements MUST consider the scope associated with each node advertisement MUST consider the scope associated with each node
administrative tag with 'per-area (or per-level) along with the administrative tag along with the area(or level in IS-IS) and the AS
area(or level in IS-IS) associated with corresponding IGP link state number of the originating node associated with corresponding IGP link
advertisement and the AS number associated with the originating node. state advertisement. The area(or level) associated with the
The area(or level) associated with corresponding IGP link state corresponding IGP link state advertisement and the AS number
advertisement and the AS number associated with the originating node associated with the originating node can be derived from appropriate
can be derived from appropriate node attributes (already defined in node attributes (already defined in BGP-LS [RFC7752]) attached with
BGP-LS [RFC7752]) attached with the corresponding Node NLRI. the corresponding Node NLRI. [RFC7752] specifies that ISIS level
information be encoded in Node NLRI [1] and OSPF Area Identifiers be
encoded in Node Descriptor Sub-TLVs [2].
3. BGP-LS Extensions for Per-Node Administrative Tags 3. BGP-LS Extensions for Per-Node Administrative Tags
The BGP-LS NLRI can be a node NLRI, a link NLRI or a prefix NLRI. The BGP-LS NLRI can be a node NLRI, a link NLRI or a prefix NLRI.
The corresponding BGP-LS attribute is a node attribute, a link The corresponding BGP-LS attribute is a node attribute, a link
attribute or a prefix attribute. BGP-LS [RFC7752] defines the TLVs attribute or a prefix attribute. BGP-LS [RFC7752] defines the TLVs
that map link-state information to BGP-LS NLRI and BGP-LS attribute. that map link-state information to BGP-LS NLRI and BGP-LS attribute.
This document adds an new Node Attribute TLV called 'Node Admin Tag This document adds an new Node Attribute TLV called 'Node Admin Tag
TLV' to encode node administrative tags information. TLV' to encode node administrative tags information.
skipping to change at page 5, line 26 skipping to change at page 4, line 40
administrative tags. Similarly [RFC7917] defines the 'Node administrative tags. Similarly [RFC7917] defines the 'Node
Administrative Tag' TLV in OSPF Router Information LSAs to encode Administrative Tag' TLV in OSPF Router Information LSAs to encode
node administrative tags in OSPF Link State update packets. The node node administrative tags in OSPF Link State update packets. The node
administrative tags TLVs learnt from the IGP link state administrative tags TLVs learnt from the IGP link state
advertisements of a specific node will all be inserted in a new Node advertisements of a specific node will all be inserted in a new Node
Admin Tag TLV and added to the corresponding Node are mapped to the Admin Tag TLV and added to the corresponding Node are mapped to the
corresponding BGP-LS Node NLRI. Node administrative tags from IGP corresponding BGP-LS Node NLRI. Node administrative tags from IGP
advertisements are mapped to the corresponding Node Admin Tag TLV in advertisements are mapped to the corresponding Node Admin Tag TLV in
the following way. the following way.
+----------+---------------+----------+---------------+-------------+ +----------+----------------+----------+---------------+------------+
| TLV Code | Description | Length | IS-IS TLV | OSPF | | TLV Code | Description | Length | IS-IS TLV | OSPF |
| Point | | | /sub-TLV | LSA/TLV | | Point | | | /sub-TLV | LSA/TLV |
+----------+---------------+----------+---------------+-------------+ +----------+----------------+----------+---------------+------------+
| TBD | Node Admin | Variable | 242/TBD [1] | RI-LSA/TBD | | TBD | Node Admin Tag | Variable | 242/21 [3] | RI-LSA/10 |
| | Tag TLV | | | [2] | | | TLV | | | [4] |
+----------+---------------+----------+---------------+-------------+ +----------+----------------+----------+---------------+------------+
Table 1: Node Admin Tag TLV Mapping from IGP Table 1: Node Admin Tag TLV Mapping from IGP
3.1. Node Admin Tag TLV 3.1. Node Admin Tag TLV
The new Node Administrative Tag TLV, like other BGP-LS Node Attribute The new Node Administrative Tag TLV, like other BGP-LS Node Attribute
TLVs, is formatted as Type/Length/Value (TLV)triplets. Figure 2 TLVs, is formatted as Type/Length/Value (TLV)triplets. Figure 1
below shows the format of the new TLV. below shows the format of the new TLV.
0 1 2 3 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 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 | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Administrative Tag #1 | | Administrative Tag #1 |
skipping to change at page 6, line 49 skipping to change at page 6, line 49
The following bit flags are defined: The following bit flags are defined:
L bit : If the L bit is set (1), it signifies that L bit : If the L bit is set (1), it signifies that
all administrative flags encoded in this all administrative flags encoded in this
TLV has per-area(or level in IS-IS) scope, TLV has per-area(or level in IS-IS) scope,
and should not be mixed with ones with same and should not be mixed with ones with same
value but with 'global' scope (L bit reset value but with 'global' scope (L bit reset
to 0). to 0).
Figure 2: BGP Link-State Node Administrative Tag TLV Figure 1: BGP Link-State Node Administrative Tag TLV
This new type of 'Node Admin Tag' TLVs can ONLY be added to the Node This new type of 'Node Admin Tag' TLVs can ONLY be added to the Node
Attribute associated with the Node NLRI that originates the Attribute associated with the Node NLRI that originates the
corresponding node administrative tags in IGP domain. corresponding node administrative tags in an IGP domain.
All the node administrative tags with 'per-area' (or per-level) All the node administrative tags with 'per-area' (or per-level)
scope, originated by a single node in IGP domain SHALL be re- scope, originated by a single node in an IGP domain SHALL be re-
originated in a single 'Node Admin Tag' TLV and inserted in the Node originated in a single 'Node Admin Tag' TLV and inserted in the Node
NLRI generated for the same node. Similarly, all the node NLRI generated for the same node. Similarly, all the node
administrative tags with 'global' scope originated by the same node administrative tags with 'global' scope originated by the same node
in IGP domain SHALL be re-originated in another 'Node Admin Tag' TLV in IGP domain SHALL be re-originated in another 'Node Admin Tag' TLV
and inserted in the same Node NLRI generated for the originating and inserted in the same Node NLRI generated for the originating
node. Multiple instances of a TLV may be generated by the BGP-lS node. Multiple instances of a TLV may be generated by the BGP-LS
router for a given node in the IGP domain. This MAY happen if the router for a given node in the IGP domain. This MAY happen if the
original node's link state advertisement carries more than 16383 node original node's link state advertisement carries more than 16383 node
administrative groups and a single TLV does not provide sufficient administrative groups and a single TLV does not provide sufficient
space. As such multiple occurence of the 'Node Admin Tag' TLVs under space. As such multiple occurence of the 'Node Admin Tag' TLVs under
a single BGP LS NLRI is cumulative. a single BGP LS NLRI is cumulative.
While copying node administrative tags from IGP link-state While copying node administrative tags from IGP link-state
advertisements to corresponding BGP-LS advertisements, the said BGP- advertisements to corresponding BGP-LS advertisements, the said BGP-
LS speaker MAY run all the node administrative flags through a LS speaker MAY run all the node administrative flags through a
locally configured policy that selects which ones should be exported locally configured policy that selects which ones should be exported
and which ones not. And then the node administrative tag is copied and which ones not. And then the node administrative tag is copied
to the BGP-LS advertisement if it is permitted to do so by the said to the BGP-LS advertisement if it is permitted to do so by the said
policy. policy. Definition of such a policy is outside the scope of this
document.
4. Elements of Procedure 4. Elements of Procedure
Meaning of the Node administrative tags is generally opaque to BGP Meaning of the Node administrative tags is generally opaque to the
Link-State protocol. Router advertising the node administrative tag BGP Link-State protocol. A router advertising the node
(or tags) may be configured to do so without knowing (or even administrative tag (or tags) may be configured to do so without
explicitly supporting) functionality implied by the tag. knowing (or even explicitly supporting) functionality implied by the
tag.
Interpretation of tag values is specific to the administrative domain Interpretation of tag values is specific to the administrative domain
of a particular network operator. The meaning of a node of a particular network operator. The meaning of a node
administrative tag is defined by the network local policy and is administrative tag is defined by the network local policy. However
controlled via the configuration. However multiple administrative multiple administrative domain owners may agree on a common meaning
domain owners may agree on a common meaning implied by a implied by an administrative tag for mutual benefit.
administrative tag for mutual benefit.
The semantics of the tag order has no meaning. There is no implied The semantics of the tag order has no meaning. There is no implied
meaning to the ordering of the tags that indicates a certain meaning to the ordering of the tags that indicates a certain
operation or set of operations that need to be performed based on the operation or set of operations that need to be performed based on the
ordering. ordering.
Each tag SHOULD be treated as an independent identifier that MAY be Each tag SHOULD be treated as an independent identifier that MAY be
used in policy to perform a policy action. Node administrative tags used in policy to perform a policy action. Node administrative tags
carried by the Node Admin Tag TLV SHOULD be used to indicate a carried by the Node Admin Tag TLV SHOULD be used to indicate
independent characteristics of the node in IGP domain that originated independent characteristics of the node in the IGP domain that
it. The TLV SHOULD be considered as an unordered list. Whilst originated it. The TLV SHOULD be considered as an unordered list.
policies may be implemented based on the presence of multiple tags Whilst policies may be implemented based on the presence of multiple
(e.g., if tag A AND tag B are present), they MUST NOT be reliant upon tags (e.g., if tag A AND tag B are present), they MUST NOT be reliant
the order of the tags (i.e., all policies should be considered upon the order of the tags (i.e., all policies should be considered
commutative operations, such that tag A preceding or following tag B commutative operations, such that tag A preceding or following tag B
does not change their outcome). does not change their outcome).
For more details on guidance on usage of node administrative tags For more details on guidance regarding usage of node administrative
please refer to section 4 [3] in [RFC7917]. tags please refer to section 4 [5] in [RFC7917] or section 2.2.1 [6]
in [RFC7777].
5. Applications 5. Applications
[RFC7917] and [RFC7777] present some applications of node [RFC7917] and [RFC7777] present some applications of node
administrative tags. administrative tags.
The Policy-based Explicit routing use case can be extended to inter- The Policy-based Explicit routing use case can be extended to inter-
area or inter-AS scenarios where an end to end path needs to avoid or area or inter-AS scenarios where an end to end path needs to avoid or
include nodes that have particular properties. Following are some include nodes that have particular properties. Following are some
examples. examples.
1. Geopolitical routing : preventing traffic from country A to 1. Geopolitical routing : preventing traffic from country A to
country B to cross country C. In this case, we may use node country B to cross country C. In this case, we may use node
administrative tags to encode geographical information (country). administrative tags to encode geographical information (country).
Path computation will be required to take into account node Path computation may be required to take into account node
administrative tag to permit avoidance of nodes belonging to administrative tag to permit avoidance of nodes belonging to
country C. country C.
2. Legacy node avoidance : in some specific cases, it is interesting 2. Legacy node avoidance : in some specific cases, it is interesting
for service-provider to force some traffic to avoid legacy nodes for a service-provider to force some traffic to avoid legacy
in the network. For example, legacy nodes may not be carrier nodes in the network. For example, legacy nodes may not be
class (no high availability), and service provider wants to carrier class (no high availability), and a service provider may
ensure that critical traffic only uses nodes that are providing want to ensure that critical traffic only uses nodes that are
high availability. providing high availability.
In case of inter-AS Traffic-Engineering applications, different ASes In case of inter-AS Traffic-Engineering applications, different ASes
SHOULD share their administrative tag policies. They MAY also need SHOULD share their administrative tag policies. They MAY also need
to agree upon some common tagging policy for specific applications. to agree upon some common tagging policy for specific applications.
For more details on some possible applications with node For more details on some possible applications with node
administrative tags please refer to section 3 [4] in [RFC7777]. administrative tags please refer to section 3 [7] in [RFC7777].
6. IANA Considerations 6. IANA Considerations
This document requests assigning code-points from the registry for This document requests assigning code-points from the registry for
BGP-LS attribute TLVs based on table Table 2. BGP-LS attribute TLVs based on Table 2.
7. Manageability Considerations 7. Manageability Considerations
This section is structured as recommended in [RFC5706]. This section is structured as recommended in [RFC5706].
7.1. Operational Considerations 7.1. Operational Considerations
7.1.1. Operations 7.1.1. Operations
Existing BGP and BGP-LS operational procedures apply. No new Existing BGP and BGP-LS operational procedures apply. No new
operation procedures are defined in this document. operational procedures are defined in this document.
8. TLV/Sub-TLV Code Points Summary 8. TLV/Sub-TLV Code Points Summary
This section contains the global table of all TLVs/Sub-TLVs defined This section contains the global table of all TLVs/Sub-TLVs defined
in this document. in this document.
+----------------+----------------+----------+ +----------------+----------------+----------+
| TLV Code Point | Description | Length | | TLV Code Point | Description | Length |
+----------------+----------------+----------+ +----------------+----------------+----------+
| 1040 | Node Admin Tag | variable | | 1040 | Node Admin Tag | variable |
skipping to change at page 10, line 40 skipping to change at page 10, line 45
RFC 7777, DOI 10.17487/RFC7777, March 2016, RFC 7777, DOI 10.17487/RFC7777, March 2016,
<http://www.rfc-editor.org/info/rfc7777>. <http://www.rfc-editor.org/info/rfc7777>.
[RFC7917] Sarkar, P., Ed., Gredler, H., Hegde, S., Litkowski, S., [RFC7917] Sarkar, P., Ed., Gredler, H., Hegde, S., Litkowski, S.,
and B. Decraene, "Advertising Node Administrative Tags in and B. Decraene, "Advertising Node Administrative Tags in
IS-IS", RFC 7917, DOI 10.17487/RFC7917, July 2016, IS-IS", RFC 7917, DOI 10.17487/RFC7917, July 2016,
<http://www.rfc-editor.org/info/rfc7917>. <http://www.rfc-editor.org/info/rfc7917>.
11.3. URIs 11.3. URIs
[1] http://tools.ietf.org/html/rfc7917#section-3.1 [1] http://tools.ietf.org/html/rfc7752#section-3.2
[2] http://tools.ietf.org/html/rfc7777#section-2.1 [2] http://tools.ietf.org/html/rfc7752#section-3.2.1.4
[3] http://tools.ietf.org/html/rfc7917#section-4 [3] http://tools.ietf.org/html/rfc7917#section-3.1
[4] http://tools.ietf.org/html/rfc7777#section-3 [4] http://tools.ietf.org/html/rfc7777#section-2.1
[5] http://tools.ietf.org/html/rfc7917#section-4
[6] http://tools.ietf.org/html/rfc7777#section-2.2.1
[7] http://tools.ietf.org/html/rfc7777#section-3
Authors' Addresses Authors' Addresses
Pushpasis Sarkar (editor) Pushpasis Sarkar (editor)
Arrcus, Inc. Arrcus, Inc.
Email: pushpasis.ietf@gmail.com Email: pushpasis.ietf@gmail.com
Hannes Gredler Hannes Gredler
RtBrick, Inc. RtBrick, Inc.
Email: hannes@rtbrick.com Email: hannes@rtbrick.com
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