Internet DRAFT - draft-chen-bgp-ls-security-capability
draft-chen-bgp-ls-security-capability
Internet Engineering Task Force Chen, Ed.
Internet-Draft L. Su
Intended status: Informational China Mobile
Expires: 11 May 2023 7 November 2022
the extensions of BGP-LS to carry security capabilities
draft-chen-bgp-ls-security-capability-00
Abstract
The goal is to collect the security capabilities of nodes, which will
be one of the factors to form the routing topology, and use the
routing programming capabilities to form a secure routing path.
The BGP-LS protocol is extended to carry the security capabilities of
the node. The controller collects topology information, forms a
topology path with security capabilities according to security
requirements, and supports SRv6 path sending to execute node
forwarding through programming.
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/.
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 11 May 2023.
Copyright Notice
Copyright (c) 2022 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
Chen & Su Expires 11 May 2023 [Page 1]
Internet-Draft BGP-LS2C November 2022
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 . . . . . . . . . . . . . . . . . . . . . . . . 2
2. BGP-LS node type carries security capability . . . . . . . . 3
2.1. Collection model of security capabilities . . . . . . . . 3
2.2. New Node Attribute TLVs . . . . . . . . . . . . . . . . . 3
2.3. Usage of new attribute . . . . . . . . . . . . . . . . . 5
3. BGP-LS Link type carries security capability . . . . . . . . 5
3.1. Collection model of security capabilities . . . . . . . . 5
3.2. New Link Attribute TLVs . . . . . . . . . . . . . . . . . 6
3.3. Useage of new attribute . . . . . . . . . . . . . . . . . 8
4. BGP-LS Prefix type carries security capability . . . . . . . 8
4.1. Collection model of security capabilities . . . . . . . . 9
4.2. New Link Attribute TLVs . . . . . . . . . . . . . . . . . 9
4.3. Usage of new attribute . . . . . . . . . . . . . . . . . 11
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction
The most important reason for using BGP-LS as the extended basic
protocol is that BGP-LS shields the differences of other routing
protocols, and the underlying routing protocol types do not need to
be considered when transmitting security capabilities.
RFC7752 standardized North-Bound Distribution of Link-State and
Traffic Engineering (TE) Information Using BGP, describes a mechanism
by which link-state and TE information can be collected from networks
and shared with external components using the BGP routing protocol,
using a new BGP Network Layer Reachability Information (NLRI)
encoding format.
BGP-LS is a new way to collect network topology. The topology
information discovered by the IGP protocol is summarized by the BGP
protocol and sent to the upper controller. With the powerful routing
and routing capabilities of the BGP protocol, there are three types
of BGP-LS routes, which are used to carry node, link and route prefix
information respectively. The three routes cooperate with each other
to complete the transmission of topology information. The node
routing function is to record the node information of the topology,
the link routing function is to record the link information between
two devices, and the address prefix routing function is to record the
network segment information that the node can reach.
Chen & Su Expires 11 May 2023 [Page 2]
Internet-Draft BGP-LS2C November 2022
The state information NLRI collected by BGP-LS is described in TLV
(type/length/value triplet) format. Each link state described by
NLRI can identify a node, link or prefix. Therefore, three types of
NLRI are newly set in the standard, of which type 3 and 4 are used to
distinguish the prefix of IPv4 and IPv6. There are only two types of
NLRI attributes in the original BGP protocol: MP_ REACH_ NLRI,
attribute type 14; MP_ UNREACH_ NLRI, attribute type 15.
2. BGP-LS node type carries security capability
2.1. Collection model of security capabilities
+----------+
+--------+Controller+-----------+
| +----------+ |
BGP-LS(Node) |
| |
xxxxxxxx|xxxxxxxxx |
x | x |
x +-----+-+ x +-----+-+
x |Router | x |Router |
x +----+--+ x +-+---+-+
x | x | |
x | x +------+ |
x | x | |
x +----+----+ x +---+----+ +--+-----+
x |Security | x |Security| |Security|
x |Products | x |Products| |Products|
x +---------+ x +--------+ +--------+
xxxxxxxxxxxxxxxxxx
Figure1: Router and attached security products are used as node units
2.2. New Node Attribute TLVs
The Local Node Descriptors TLV contains Node Descriptors for the node
anchoring the local end of the link. This is a mandatory TLV in all
three types of NLRIs (node, link, and prefix).
Chen & Su Expires 11 May 2023 [Page 3]
Internet-Draft BGP-LS2C November 2022
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// Node Descriptor Sub-TLVs (variable) //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Local Node Descriptors TLV Format
Node attribute TLVs are the TLVs that may be encoded in the BGP-LS
attribute with a Node NLRI. The following Node Attribute TLVs are
defined:
+-------------+----------------------+----------+
| TLV Code | Description | Length |
| Point | | |
+-------------+----------------------+----------+
| 263 | Multi-Topology | variable |
| | Identifier | |
| 1024 | Node Flag Bits | 1 |
| 1025 | Opaque Node | variable |
| | Attribute | |
| 1026 | Node Name | variable |
| 1027 | IS-IS Area | variable |
| | Identifier | |
| 1028 | IPv4 Router-ID of | 4 |
| | Local Node | |
| 1029 | IPv6 Router-ID of | 16 |
| | Local Node | |
+-------------+----------------------+----------+
Table 3: Node Attribute TLVs
The security capability is transferred by adding the security
capability attribute to the attributes of the local node.
+-------------+----------------------+----------+
| TLV Code | Description | Length |
| Point | | |
+-------------+----------------------+----------+
| 1030 | Node Security | variable |
| | Capability | |
+-------------+----------------------+----------+
Table 4: New Node Attribute TLV
Chen & Su Expires 11 May 2023 [Page 4]
Internet-Draft BGP-LS2C November 2022
2.3. Usage of new attribute
When programming the routing path, take the security capability
requirement as one of the inputs. The description of the security
capability requirement can be structured or one-dimensional matrix,
which only needs to be consistent with the router's security
capability description; There are many routing rules. After
introducing security capability requirements, it is necessary to
dynamically adjust the security capability as the position of routing
rules according to the requirements. The main rule strategies are:
① Select the routing node that meets the security requirements
as the forwarding node when the path is reachable; ② Select the
shortest path when all the safety requirements are met; ③ When
the same path length and security requirements are met, select the
path with small load for forwarding.
3. BGP-LS Link type carries security capability
3.1. Collection model of security capabilities
+----------+
+--------+Controller+-----------+
| +----------+ |
| |
| |
xxxxxxxxxxxxxxxxxx |
x | x |
x +-----+-+ x BGP-LS(Link) +-----+-+
x |Router |----x------------------|Router |
x +----+--+ x +-+---+-+
x | x | |
x | x +------+ |
x | x | |
x +----+----+ x +---+----+ +--+-----+
x |Security | x |Security| |Security|
x |Products | x |Products| |Products|
x +---------+ x +--------+ +--------+
xxxxxxxxxxxxxxxxxx
Figure 5: The peer node transmits the security capability through the link
Chen & Su Expires 11 May 2023 [Page 5]
Internet-Draft BGP-LS2C November 2022
The router and its attached security products are the basic units.
When collecting status information, only some nodes can directly
transmit the node status information to the controller through the
BGP-LS protocol. Other nodes that do not directly transmit the node
information need to transmit the node information to the direct node
to achieve the transmission of security capability information.
Therefore, for non direct nodes, It is required to report its own
security capability information through the BGP-LS link state data
packet.
3.2. New Link Attribute TLVs
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
+-+-+-+-+-+-+-+-+
| Protocol-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier |
| (64 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Local Node Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Remote Node Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Link Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: The Link NLRI Format
Chen & Su Expires 11 May 2023 [Page 6]
Internet-Draft BGP-LS2C November 2022
+-----------+---------------------+--------------+
| TLV Code | Description | IS-IS TLV |
| Point | | /Sub-TLV |
+-----------+---------------------+--------------+
| 1028 | IPv4 Router-ID of | 134/--- |
| | Local Node | |
| 1029 | IPv6 Router-ID of | 140/--- |
| | Local Node | |
| 1030 | IPv4 Router-ID of | 134/--- |
| | Remote Node | |
| 1031 | IPv6 Router-ID of | 140/--- |
| | Remote Node | |
| 1088 | Administrative | 22/3 |
| | group (color) | |
| 1089 | Maximum link | 22/9 |
| | bandwidth | |
| 1090 | Max. reservable | 22/10 |
| | link bandwidth | |
| 1091 | Unreserved | 22/11 |
| | bandwidth | |
| 1092 | TE Default Metric | 22/18 |
| 1093 | Link Protection | 22/20 |
| | Type | |
| 1094 | MPLS Protocol Mask | --- |
| 1095 | IGP Metric | --- |
| 1096 | Shared Risk Link | --- |
| | Group | |
| 1097 | Opaque Link | --- |
| | Attribute | |
| 1098 | Link Name | --- |
+-----------+---------------------+--------------+
Table 7: Link Attribute TLVs
The new attribute describes the link security capability and
transmits the link security capability information through this
attribute.
+-----------+---------------------+--------------+
| TLV Code | Description | IS-IS TLV |
| Point | | /Sub-TLV |
+-----------+---------------------+--------------+
| 1099 | Link security info | --- |
+-----------+---------------------+--------------+
Table 8: New Link Attribute TLVs
Chen & Su Expires 11 May 2023 [Page 7]
Internet-Draft BGP-LS2C November 2022
3.3. Useage of new attribute
+------+ +------+
| A | | B |
+---+--+ +--+---+
|SCicg A |
+--------------->|
| SCing B |
<----------------+
|SCing <A,B> |
+---------------->
| |
Figure 9: Assosiation security capability interaction
The Assosiation security capability depends on the security
capability enabled by the node. As a node directly connected to the
controller, node B first interacts with the enabled security
capability information of the opposite end in a two-way manner, and
then the opposite end initiates the transmission of the assosiation
security capability information.
The decision of assosiation security capability can be divided into
two situations: one is under the same security domain, and the other
is under different security domains. 1. The decision rules for link
security capabilities under different security domains are as
follows: SCing represents the enabled security capabilities of a
node. Example: SCing A=[1,0,0,1,0,......]，SCing
B=[1,1,0,1,0,......]，SCing Assosiation<A,B> = SCing A && SCing
B
When the link passes through more than two nodes, it is necessary to
logically and operate the security capabilities of all nodes in the
path to obtain the link security capabilities.
1. The decision rules of assosiation security capability in the same
security domain are as follows: SCing indicates the security
capability of a node that has been enabled. Example: SCing
A=[1,0,0,1,0,......]，SCing
B=[1,1,0,1,0,......]，SCing Assosiation<A,B> = SCing A ||
SCing B
When the link passes through more than two nodes, it is necessary to
logically or operate the security capabilities of all nodes in the
path to obtain the link security capabilities.
4. BGP-LS Prefix type carries security capability
Chen & Su Expires 11 May 2023 [Page 8]
Internet-Draft BGP-LS2C November 2022
4.1. Collection model of security capabilities
+----------+ +----------+
+Controller+ +Controller+
+----------+ +----------+
| |
| AS 100 |
xxxxxxxxxxxxxxxxxx |AS 200
x | x xxxxxxx|xxxxxxxx
x +-----+-+ x BGP-LS(Prefix) x +-----+-+ x
x |RouterA|----x-----------------x--|RouterE| x
x +----+--+ x x +-+---+-+ x
x | x xxxxxxxxxxx | | x
x | x x +------+ | x
x | x x | | x
x +----+--+ x x +---+--+ +--+---+ x
x |Router | x x |Router|--|Router| x
x +-------+ x x +------+ +------+ x
xxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx
Figure 10: Security capability is transferred between ASs through Prefix
The router and its attached security products are the basic units.
When collecting the status information, only some nodes can directly
transmit the node status information to the controller through the
BGP-LS protocol. Other nodes that do not directly transmit the node
information need to transmit the node information to the directly
connected node to achieve the transmission of security capability
information. In the figure, nodes A and E are direct connected
nodes, which are connected to their respective controllers. Nodes A
and E are responsible for collecting the security capabilities of
other nodes in their respective fields.
4.2. New Link Attribute TLVs
The IPv4 and IPv6 Prefix NLRIs (NLRI Type = 3 and Type = 4) use the
same format, as shown in the following figure.
Chen & Su Expires 11 May 2023 [Page 9]
Internet-Draft BGP-LS2C November 2022
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
+-+-+-+-+-+-+-+-+
| Protocol-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier |
| (64 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Local Node Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Prefix Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 11: The IPv4/IPv6 Topology Prefix NLRI Format
+---------------+----------------------+----------+
| TLV Code | Description | Length |
| Point | | |
+---------------+----------------------+----------+
| 1152 | IGP Flags | 1 |
| 1153 | IGP Route Tag | 4*n |
| 1154 | IGP Extended Route | 8*n |
| | Tag | |
| 1155 | Prefix Metric | 4 |
| 1156 | OSPF Forwarding | 4 |
| | Address | |
| 1157 | Opaque Prefix | variable |
| | Attribute | |
+---------------+----------------------+----------+
Table 12: Prefix Attribute TLVs
An AS has at least one super direct connection node, which has the
security capability information of all nodes under the AS. By adding
new attributes to Prefix, the security capabilities of the entire AS
can be transferred.
+---------------+--------------------------+----------+
| TLV Code | Description | Length |
| Point | | |
+---------------+--------------------------+----------+
| 1158 | AS security capabilities | variable |
+---------------+--------------------------+----------+
AS Security capabilities means the security capability information of
all nodes under the AS, that is, the security capability information
of all nodes is spliced, such as {[IP address (A)+node security
capability], [IP address (B)+node security capability]...}.
Chen & Su Expires 11 May 2023 [Page 10]
Internet-Draft BGP-LS2C November 2022
4.3. Usage of new attribute
5. IANA Considerations
This memo includes no request to IANA.
6. Security Considerations
TBD
Authors' Addresses
Meiling Chen (editor)
China Mobile
BeiJing
China
Email: chenmeiling@chinamobile.com
Li Su
China Mobile
BeiJing
China
Email: suli@chinamobile.com
Chen & Su Expires 11 May 2023 [Page 11]
