Network Working Group R. Bush
Internet-Draft Arrcus & IIJ
Intended status: Standards Track K. Patel
Expires: October 29, 2019 Arrcus
April 27, 2019
L3DL Upper Layer Protocol Configuration
draft-ymbk-lsvr-l3dl-ulpc-00
Abstract
This document users the Layer 3 Liveness and Discovery protocol to
communicate the parameters needed to exchange inter-device Upper
Layer Protocol Configuration for upper layer protocols such as the
BGP family.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
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
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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 October 29, 2019.
Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Reading and Terminology . . . . . . . . . . . . . . . . . . . 2
3. Upper Layer Protocol Configuration PDU . . . . . . . . . . . 3
3.1. BGP ULPC Attribute sub-TLVs . . . . . . . . . . . . . . . 3
3.1.1. BGP ASN . . . . . . . . . . . . . . . . . . . . . . . 4
3.1.2. BGP IPv4 Address . . . . . . . . . . . . . . . . . . 4
3.1.3. BGP IPv6 Address . . . . . . . . . . . . . . . . . . 5
3.1.4. BGP Authentication sub-TLV . . . . . . . . . . . . . 5
3.1.5. BGP Miscellaneous Flags . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.1. Normative References . . . . . . . . . . . . . . . . . . 7
6.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
Massive Data Centers (MDCs) which use upper layer protocols such as
BGP4, BGP-LS, BGP-SPF, etc. may use the Layer 3 Liveness and
Discovery Protocol, L3DP, [I-D.ietf-lsvr-l3dl] to reveal the inter-
device links of the topology. It is desirable for devices to
facilitate the configuration parameters of those upper layer
protocols to enable more hands-free configuration. This document
defines a new L3DP PDU to communicate these Upper Layer Protocol
Configuration parameters.
2. Reading and Terminology
The reader is assumed to have read Layer 3 Discovery and Liveness
[I-D.ietf-lsvr-l3dl]. The terminology and PDUs there are assumed
here.
Familiarity with the BGP4 Protocol [RFC4271] is assumed. Familiarity
with BGP-SPF, [I-D.ietf-lsvr-bgp-spf], might be useful.
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3. Upper Layer Protocol Configuration PDU
To communicate parameters required to configure peering and operation
of Upper Layer Protocols at IP layer 3 and above, e.g., BGP sessions
on a link, a neutral sub-TLV based Upper Layer Protocol PDU is
defined as follows:
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 = 8 | Payload Length | ULPC Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AttrCount | Attribute List ... ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sig Type | Signature Length | Signature ... ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Type and Payload Length are defined in [I-D.ietf-lsvr-l3dl].
ULPC Type:
Bit 0 : BGP
Bit 1-15: Must be 0
The AttrCount is the number of attribute sub-TLVs in the Attribute
List.
The Attribute List is a, possibly null, set of sub-TLVs describing
the configuration attributes of the specific upper layer protocol.
3.1. BGP ULPC Attribute sub-TLVs
The parameters needed for BGP peering on a link are exchanged in sub-
TLVs within an Upper Layer Protocol PDU. The following describe the
various sub-TLVs for BGP.
The goal is to provide the minimal set of configuration parameters
needed by BGP OPEN to successfully start a BGP peering. The goal is
specifically not to replace or conflict with data exchanged during
BGP OPEN. Multiple sources of truth are a recipe for complexity and
hence pain.
If there are multiple BGP sessions on a link, e.g., IPv4 and IPv6,
then multiple sets of BGP sub-TLVs are exchanged within the BGP ULPC
PDU.
A peer receiving BGP ULPC PDUs has only one active BGP ULPC PDU at
any point in time; receipt of a new BGP ULPC PDU replaces any
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previous one. If there are one or more open BGP sessions, receipt of
a new BGP ULPC PDU does not affect these sessions.
As a link may have multiple encapsulations and multiple addresses for
an IP encapsulation, which address of which encapsulation are to be
used for the BGP session MUST be specified.
For each BGP peering on a link here MUST be one agreed encapsulation,
and the addresses used MUST be in the corresponding L3DP IPv4/IPv6
Announcement PDUs. If a peering address has been announced as a
loopback, a two or three (one or both ends could be loopbacks) hop
BGP session will be established. Otherwise a direct one hop session
is used.
3.1.1. BGP ASN
The Autonomous System number MUST be specified. If the AS Number is
less than 32 bits, it is padded with high order zeros.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Attr Type = 1 | Attr Len = 48 | My ASN ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.1.2. BGP IPv4 Address
The BGP IPv4 Address sub-TLV announces the sender's IPv4 BGP peering
source address to be used by the receiver. At least one of IPv4 or
IPv6 BGP source addresses MUST be announced.
As usual, the BGP OPEN capability negotiation will determine the AFI/
SAFIs to be transported over the peering, see [RFC4760] .
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Attr Type = 2 | Attr Len = 56 | My IPv4 Peering Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ | Prefix Len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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3.1.3. BGP IPv6 Address
The BGP IPv6 Address sub-TLV announces the sender's IPv6 BGP peering
source address to be used by the receiver. At least one of IPv4 or
IPv6 BGP source addresses MUST be announced.
As usual, the BGP OPEN capability negotiation will determine the AFI/
SAFIs to be transported over the peering, see [RFC4760] .
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Attr Type = 3 | Attr Len = 152| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| |
+ +
| My IPv6 Peering Address |
+ +
| |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | Prefix Len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.1.4. BGP Authentication sub-TLV
The BGP Authentication sub-TLV provides any authentication data
needed to OPEN the BGP session. Depending on operator configuration
of the environment, it might be a simple MD5 key (see [RFC2385]), the
name of a key chain a KARP database (see [RFC7210]), or one of
multiple Authentication sub-TLVs to support hop[RFC4808].
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Attr Type = 4 | Attr Len | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~
~ BGP Authentication Data ... ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.1.5. BGP Miscellaneous Flags
The BGP session OPEN has extensive, and a bit complex, capability
negotiation facilities. In case one or more extra attributes might
be needed, the BGP Miscellaneous Flags sub-TLV may be used. No flags
are currently defined.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Attr Type = 5 | Attr Len = 32 | Misc Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Misc Attrs:
Bit 0: Ghu knows what
Bit 1-15: Must be zero
4. Security Considerations
All the Security considerations of [I-D.ietf-lsvr-l3dl] apply to this
PDU.
As the ULPC PDU may contain keying material, see Section 3.1.4, it
SHOULD BE signed.
Any keying material in the PDU SHOULD BE salted ad hashed.
The BGP Authentication sub-TLV provides for provisioning MD5, which
is a quite weak hash, horribly out of fashion, and kills puppies.
But, like it or not, it is what BGP deployments use.
5. IANA Considerations
This document requests the IANA create a new entry in the L3DL PDU
Type registry as follows:
PDU
Code PDU Name
---- -------------------
9 ULPC
This document requests the IANA create a registry for L3DL ULPC Type,
which may range from 0 to 255. The name of the registry should be
L3DL-ULPC-Type. The policy for adding to the registry is RFC
Required per [RFC5226], either standards track or experimental. The
initial entries should be the following:
Bit Bit Name
---- -------------------
0 Reserved
1 BGP
2-255 Reserved
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6. References
6.1. Normative References
[I-D.ietf-lsvr-l3dl]
Bush, R., Austein, R., and K. Patel, "Layer 3 Discovery
and Liveness", draft-ietf-lsvr-l3dl-00 (work in progress),
April 2019.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006,
<http://www.rfc-editor.org/info/rfc4271>.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007,
<http://www.rfc-editor.org/info/rfc4760>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <http://www.rfc-editor.org/info/rfc8174>.
6.2. Informative References
[I-D.ietf-lsvr-bgp-spf]
Patel, K., Lindem, A., Zandi, S., and W. Henderickx,
"Shortest Path Routing Extensions for BGP Protocol",
draft-ietf-lsvr-bgp-spf-04 (work in progress), December
2018.
[RFC2385] Heffernan, A., "Protection of BGP Sessions via the TCP MD5
Signature Option", RFC 2385, DOI 10.17487/RFC2385, August
1998, <http://www.rfc-editor.org/info/rfc2385>.
[RFC4808] Bellovin, S., "Key Change Strategies for TCP-MD5",
RFC 4808, DOI 10.17487/RFC4808, March 2007,
<http://www.rfc-editor.org/info/rfc4808>.
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[RFC7210] Housley, R., Polk, T., Hartman, S., and D. Zhang,
"Database of Long-Lived Symmetric Cryptographic Keys",
RFC 7210, DOI 10.17487/RFC7210, April 2014,
<http://www.rfc-editor.org/info/rfc7210>.
Authors' Addresses
Randy Bush
Arrcus & IIJ
5147 Crystal Springs
Bainbridge Island, WA 98110
United States of America
Email: randy@psg.com
Keyur Patel
Arrcus
2077 Gateway Place, Suite #400
San Jose, CA 95119
United States of America
Email: keyur@arrcus.com
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