Network Working Group S. Bhandari
Internet-Draft S. Gundavelli
Intended status: Standards Track Cisco Systems
Expires: April 30, 2015 J. Korhonen
Renesas Mobile
M. Grayson
Cisco Systems
October 27, 2014
Access Network Identifier Option in DHCP
draft-ietf-dhc-access-network-identifier-04
Abstract
This document specifies the format and mechanism that is to be used
for encoding access network identifiers in DHCPv4 and DHCPv6 messages
by defining new access network identifier options and sub-options.
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 http://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 April 30, 2015.
Copyright Notice
Copyright (c) 2014 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
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Provisions Relating to IETF Documents
(http://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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. DHCPv4 Access-Network-Identifier Option . . . . . . . . . . . 5
4.1. DHCPv4 Access-Network-Identifier sub-options . . . . . . . 5
4.2. DHCPv4 Access-Technology-Type sub-option . . . . . . . . . 6
4.3. DHCPv4 Network-Identifier sub-options . . . . . . . . . . 7
4.3.1. DHCPv4 Network name sub-option . . . . . . . . . . . . 7
4.3.2. DHCPv4 Access-Point name sub-option . . . . . . . . . 8
4.3.3. DHCPv4 Access-Point BSSID sub-option . . . . . . . . . 9
4.4. DHCPv4 Operator identifier sub-options . . . . . . . . . . 9
4.4.1. DHCPv4 Operator Enterprise ID sub-option . . . . . . . 9
4.4.2. DHCPv4 Operator Realm sub-option . . . . . . . . . . . 10
5. DHCPv6 Access-Network-Identifier options . . . . . . . . . . . 10
5.1. DHCPv6 Access-Network-Type option . . . . . . . . . . . . 11
5.2. DHCPv6 Network-Identifier options . . . . . . . . . . . . 12
5.2.1. DHCPv6 Network Name option . . . . . . . . . . . . . . 12
5.2.2. DHCPv6 Access-Point Name option . . . . . . . . . . . 12
5.2.3. DHCPv6 Access-Point BSSID option . . . . . . . . . . . 13
5.3. Operator identifier options . . . . . . . . . . . . . . . 13
5.3.1. Operator Enterprise ID option . . . . . . . . . . . . 13
5.3.2. Operator Realm option . . . . . . . . . . . . . . . . 14
6. Client Behavior . . . . . . . . . . . . . . . . . . . . . . . 15
7. Relay Agent Behavior . . . . . . . . . . . . . . . . . . . . . 15
8. Server Behavior . . . . . . . . . . . . . . . . . . . . . . . 15
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
10. Security Considerations . . . . . . . . . . . . . . . . . . . 17
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
12.1. Normative References . . . . . . . . . . . . . . . . . . . 18
12.2. Informative References . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
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1. Introduction
Access network identification of a network device has a range of
applications. For example the local mobility anchor in a Proxy
Mobile IPv6 domain is able to provide access network and access
operator specific handling or policing of the mobile node traffic
using information about the access network to which the mobile node
is attached.
This document specifies Dynamic Host Configuration Protocol v4
(DHCPv4) [RFC2131] and Dynamic Host Configuration Protocol for IPv6
(DHCPv6) [RFC3315] options for access network identification that is
added by Client or Relay agent in the DHCPv4 or DHCPv6 messages
towards the Server.
Dynamic Host Configuration Protocol (DHCP) client or DHCP relay agent
aware of the access network and access operator add this information
in the DHCP messages. This information can be used to provide
differentiated services and policing of traffic based on the access
network to which a client is attached. Examples of how this
information can be used in mobile networks can be found in .
[RFC6757].
2. Motivation
Proxy mobile IPv6 [RFC5213] can be used for supporting network-based
mobility management in various types of network deployments. The
network architectures, such as Service provider Wi-Fi access
aggregation or, WLAN integrated mobile packet core are examples where
Proxy Mobile IPv6 is a component of the overall architecture. Some
of these architectures require the ability of the local mobility
anchor (LMA) [RFC5213] to provide differentiated services and
policing of traffic to the mobile nodes based on the access network
to which they are attached. Policy systems in mobility architectures
such as PCC [TS23203] and ANDSF [TS23402] in 3GPP system allow
configuration of policy rules with conditions based on the access
network information. For example, the service treatment for the
mobile node's traffic may be different when they are attached to a
access network owned by the home operator than when owned by a
roaming partner. The service treatment can also be different based
on the configured Service Set Identifiers (SSID) in case of IEEE
802.11 based access networks. Other examples of services include the
operator's ability to apply tariff based on the location.
The PMIPv6 extension as specified in [RFC6757] defines PMIPv6 options
to carry access network identifiers in PMIPv6 signaling from Mobile
Access Gateway (MAG) to LMA. MAG can learn this information from
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DHCP options as inserted by DHCP client or Relay agent before MAG.
If MAG relays DHCP messages to LMA as specified in [RFC5844] this
information can be inserted by MAG towards LMA in the forwarded DHCP
messages.
Figure 1 illustrates an example Proxy Mobile IPv6 deployment where
Access Points (AP) acting as a DHCP relay agent inserts access
network identifiers in DHCP messages relayed from the connected
clients. The mobile access gateway learns this information over DHCP
and delivers the information elements related to the access network
to the local mobility anchor over Proxy Mobile IPv6 signaling
messages. In this example, the additional information could comprise
the SSID of the used IEEE 802.11 network and the identities of the
operators running the IEEE 802.11 access network infrastructure.
SSID: IETF-1
Operator-Id: provider1.example
+--+ DHCP
|AP|-------. {Access Specific Policies)
+--+ | _-----_ |
+-----+ _( )_ +-----+
| MAG |-=====( PMIPv6 )======-| LMA |-
+-----+ (_ Tunnel_) +-----+
+--+ DHCP | '-----'
|AP|-------'
+--+
SSID: IETF-2
Operator-Id: provider2.example
Access Networks attached to MAG
3. Terminology
All the DHCP related terms used in this document are to be
interpreted as defined in the Dynamic Host Configuration Protocol
(DHCPv4) [RFC2131] and Dynamic Host Configuration Protocol for IPv6
(DHCPv6) [RFC3315] specifications. DHCP message refers to both
DHCPv4 and DHCPv6 messages throughout this document.
All the mobility related terms used in this document are to be
interpreted as defined in the Proxy Mobile IPv6 specifications
[RFC5213] and [RFC5844]. Additionally, this document uses the
following abbreviations:
Service Set Identifier Service Set Identifier (SSID)
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Service Set Identifier Service Set Identifier (SSID) identifies
the name of the IEEE 802.11 network. SSID differentiates from one
network to the other.
Vendor ID
The Vendor ID is the SMI Network Management Private Enterprise
Code of the IANA-maintained Private Enterprise Numbers registry
[SMI].
4. DHCPv4 Access-Network-Identifier Option
Access network identifier option carries information to identify the
access network to which the client is attached. This information
includes access technology type, network identifier and access-
network operator identifiers.
The format of the DHCPv4 Access-Network-Identifier option is shown
below.
Code Len ANI Sub-options
+------+------+------+------+------+-- --+-----+
| code | len | s1 | s2 | s2 | ... | sn |
+------+------+------+------+------+-- --+-----+
code (8-bits)
8-bit code carrying Access Network Identifier sub-options, Added
by client: OPTION_ACCESS_NETWORK_ID <IANA-0> To be assigned by
IANA.
len (8-bits)
Total length of the included sub-options
Client inserts Access Network Identifier option that contains one or
more suboptions, as defined in Section 4.1. Relay agent that wants
to include Access Network Indentifer information includes one or more
sub-options (see Section 4.1) in Relay Agent Information option
[RFC3046].
4.1. DHCPv4 Access-Network-Identifier sub-options
Access network identifier information will be defined in multiple
sub-options.
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ANI Sub-options: The ANI Sub-options consists of a sequence of
SubOptCode/Length/Value tuples for each sub-option, encoded in the
following manner:
SubOpt Len Sub-option Value
+------+------+------+------+------+------+--...-+------+
| code | N | s1 | s2 | s3 | s4 | | sN |
+------+------+------+------+------+------+--...-+------+
ANI Sub-options are defined in following sections.
(postamble)
The initial assignment of DHCP access network identifier Sub-options
is as follows:
+================+========================================+
| SUBOPTION CODE | SUBOPTION DESCRIPTION |
+================+========================================+
| <IANA-1> | Access Technology Type Suboption |
+=========================================================+
| <IANA-2> | Access Network Name Suboption |
+=========================================================+
| <IANA-3> | Access Point Name Suboption |
+=========================================================+
| <IANA-4> | Access Point BSSID Sub-option |
+=========================================================+
| <IANA-5> | Operator-Identifier Sub-option |
+=========================================================+
| <IANA-6> | Operator-Realm Sub-option |
+=========================================================+
4.2. DHCPv4 Access-Technology-Type sub-option
This sub-option is used for exchanging the type of the access
technology of the network to which the client is attached. Its
format is 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
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| suboption-code| Length | ATT | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
suboption code (8 bits)
8-bit code, it should be set to value of <IANA-1> ;, indicating
that its a Access-Network-Type sub-option.
Length (1 octet)
8-bit unsigned integer indicating the length of this suboption in
octets, excluding the suboption-code and length fields. This
field must be set to a value of (1).
Access-Technology-Type (ATT)
An 8-bit field that specifies the access technology through which
the client is connected to the access link. The values is as
populated from the IANA name space Access Technology Type Option
type value registry defined in [RFC5213].
4.3. DHCPv4 Network-Identifier sub-options
These sub-options are used for carrying the name of the access
network (e.g., a SSID in case of IEEE 802.11 Access Network, or PLMN
Identifier [TS23003] in case of 3GPP access ) and Access Point name,
to which the client is attached. The format of these sub-options is
defined the following sections.
4.3.1. DHCPv4 Network name sub-option
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|SubOption Code | Length | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Name (e.g., SSID or PLMNID) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
SubOption Code (8 bits)
8-bit code, it should be set to value of <IANA-2> , indicating
that its a Network-Name sub-option
Length (8-bits)
8-bit indicating Total length of this sub option, excluding the
suboption code and length fields. The value can be in the range
of 2 to 32 octets.
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Network Name (Variable Length)
The name of the access network to which the mobile node is
attached. The type of the Network Name is dependent on the access
technology to which the mobile node is attached. If it is 802.11
access, the Network Name MUST be the SSID of the network. If the
access network is 3GPP access, the Network Name is the PLMN
Identifier of the network. If the access network is 3GPP2 access,
the Network Name is the Access Network Identifier [ANI].
When encoding the PLMN Identifier, both the Mobile Network Code
(MNC) [TS23003] and Mobile Country Code (MCC) [TS23003] MUST be 3
digits. If the MNC in use only has 2 digits, then it MUST be
preceded with a '0'. Encoding MUST be UTF-8.
4.3.2. DHCPv4 Access-Point name sub-option
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|suboption code | Length | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Access-Point Name ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
subOption code (8 bits)
8-bit code, it should be set to value of <IANA-3> , indicating
that its a Access-Point Name sub-option
Length (1 octet)
8-bit indicating Total length of this sub option, excluding the
suboption code and length fields. The value can be in the range
of 2 to 32 octets.
Access-Point Name
The name of the access point (physical device name) to which the
mobile node is attached. This is the identifier that uniquely
identifies the access point. While Network Name (e.g., SSID)
identifies the operator's access network, Access-Point Name
identifies a specific network device in the network to which the
mobile node is attached. In some deployments, the Access-Point
Name can be set to the Media Access Control (MAC) address of the
device or some unique identifier that can be used by the policy
systems in the operator network to unambiguously identify the
device. The string is carried in UTF-8 representation.
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4.3.3. DHCPv4 Access-Point BSSID sub-option
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|suboption code | Length(6) | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Access-Point BSSID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
suboption code (8 bits)
8-bit code, it should be set to value of <IANA-4> , indicating
that its a Access-Point BSSID sub-option.
Length (1 octet)
8-bit indicating Total length of this sub option, excluding the
suboption code and length fields. The value is set to 6.
Access-Point BSSID
The 48-bit Basic service set identification(BSSID) of the access
point to which the mobile node is attached.
4.4. DHCPv4 Operator identifier sub-options
The Operator identifier sub-options can be used for carrying the
operator identifier of the access network to which the client is
attached. The format of these sub-options is defined below.
4.4.1. DHCPv4 Operator Enterprise ID sub-option
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SubOption Code| Length | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Operator Enterprise ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
SubOption Code (1-Octet)
8 bit code, It should be set to value of <IANA-5> , indicating
that it is Operator-Identifier sub-option.
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Length (1-Octet)
Total length of this sub option, excluding the suboption code and
length fields.
Operator Enterprise ID (4-Octets)
Vendor ID as a four octet Private Enterprise Number [SMI].
4.4.2. DHCPv4 Operator Realm sub-option
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| suboptioncode | Length | ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Operator Realm ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
SubOption Code (8 bits)
8 bit code. It should be set to value of <IANA-6> , indicating
that it is Operator-Realm sub-option.
Length (1 octet)
Total length of this sub option, excluding the suboption code and
length fields.
Operator Realm (Variable Length)
Realm of the operator. Realm names are required to be unique, and
are piggybacked on the administration of the DNS namespace.
Realms are encoded using a domain name encoding defined in
[RFC1035]. Up to (253) octets of the operator realm.
5. DHCPv6 Access-Network-Identifier options
The Access Network Identifier option defined here will be added by
DHCPv6 client in upstream DHCPv6 messages or by the Relay in Relay-
forward messages.
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+================+========================================+
| OPTION CODE | OPTION DESCRIPTION |
+================+========================================+
| <IANA-7> | OPTION_ANI_ATT |
+=========================================================+
| <IANA-8> | OPTION_ANI_NETWORK_NAME |
+=========================================================+
| <IANA-9> | OPTION_ANI_AP_NAME |
+=========================================================+
| <IANA-10> | OPTION_ANI_AP_BSSID |
+=========================================================+
| <IANA-11> | OPTION_ANI_OPERATOR_ID |
+=========================================================+
| <IANA-12> | OPTION_ANI_OPERATOR_REALM |
+=========================================================+
5.1. DHCPv6 Access-Network-Type option
This option is used for exchanging the type of the access technology
the client is attached to the network. Its format is 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Code | OptLen |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Access Technology Type (ATT) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code (16-bits)
16-bit code OPTION_ANI_ATT <IANA-7>
option-length (16-bits)
16-bit unsigned integer indicating length in octets of this
option. The value must be set to (1).
Access Technology Type (ATT):
Content of this is same as ATT field described in Section 4.2.
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5.2. DHCPv6 Network-Identifier options
These options can be used for carrying the name of the access network
(e.g., a SSID in case of IEEE 802.11 Access Network, or PLMN
Identifier [TS23003] in case of 3GPP access ) and Access Point name,
to which the client is attached. The format of these options is
defined below.
5.2.1. DHCPv6 Network Name option
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code | option-length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network Name (e.g., SSID or PLMNID) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code (16-bits)
16-bit code OPTION_ANI_NETWORK_NAME <IANA-8>
option-length (16-bits)
16-bit unsigned integer indicating length in octets of this
option.The value can be in the range of 2 to 32 octets.
Network Name (Variable Length)
Content of this field is same as Network Name field described in
Section 4.3.1.
5.2.2. DHCPv6 Access-Point Name option
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code | option-length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Access-Point Name ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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option-code (16-bits)
16-bit code OPTION_ANI_AP_NAME <IANA-9>
option-length (16-bits)
16-bit unsigned integer indicating length in octets of this
option.The value can be in the range of 2 to 32 octets.
Access-Point Name (Variable Length)
Content of this field is same as described in Access-Point Name
described in Section 4.3.2.
5.2.3. DHCPv6 Access-Point BSSID option
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code (TBD3) | option-length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Access-Point BSSID ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code (16-bits)
16-bit code OPTION_ANI_AP_BSSID <IANA-10>
option-length (16-bits)
16-bit unsigned integer indicating length in octets of this
option.The value is set to 6.
Access-Point BSSID (Variable Length)
Content of this field is same as described in Access-Point BSSID
described in Section 4.3.3.
5.3. Operator identifier options
The Operator identifier options can be used for carrying the operator
identifier of the access network to which the client is attached.
The format of these options is defined below.
5.3.1. Operator Enterprise ID option
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code | option-length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Operator Enterprise ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code (16-bits)
16-bit code OPTION_ANI_OPERATOR_ID <IANA-11>
option-length (16-bits)
16-bit unsigned integer indicating length in octets of this
option.
AOperator Enterprise ID
Content of this is same as Operator Enterprise ID field described
in Section 4.4.1.
5.3.2. Operator Realm option
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code | option-length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Operator Realm ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
option-code (16-bits)
OPTION_ANI_OPERATOR_REALM <IANA-12>
option-length (16-bits)
16-bit unsigned integer indicating length in octets of this
option.
Operator Realm
Content of this is same as Operator Realm field described in
Section 4.4.2.
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6. Client Behavior
DHCPv4 clients MAY include DHCPv4 ANI option define in Section 4
including one or more sub-options within the option, as defined in
sections 4.1 through 4.4 in all the upstream DHCPv4 messages to
inform the receiver about the access network it is attached to.
DHCPv6 clients MAY include DHCPv6 ANI options, as defined in Section
5.
7. Relay Agent Behavior
DHCPv4 Relay Agents MAY include sub-options defined in section 4.2
through 4.4 in the Relay Agent Information option as defined in
[RFC3046] before forwarding the DHCP message to provide information
about the access network over which DHCP messages from the client is
received. If the DHCPv4 relay agent receives DHCPv4 message already
containing access network identifier sub-options within option 82
based on its configured policy it MAY overwrite the sub-options.
DHCPv4 Relay agent MAY include the sub-options in Relay Agent
Information option even if the DHCPv4 ANI option is inserted by the
DHCPv4 client in the received DHCPv4 message based on its configured
policy.
DHCPv6 Relay Agents MAY include options defined in Section 5 in
Relay-forward message when forwarding packets from clients to the
servers to provide information about the access network over which
DHCPv6 messages from the client is received. DHCPv6 Relay Agent MAY
include options defined in Section 5 in Relay-forward message even if
the same options have been included by the DHCPv6 client in the
received DHCPv6 message based on its configured policy.
8. Server Behavior
If DHCPv4 server does not understand the option defined in Section 4
it MUST ignore the DHCPv4 Access Network Identifier option received.
If the DHCPv4 server does not understand the received sub-option
defined in sections 4.1 through 4.4 either in DHCPv4 Access Network
Identifier option or in Relay Agent Information options it MUST
ignore those sub-options only. If DHCPv4 Server is able to process
the DHCPv4 Access Network Identifier and sub-options defined in
sections 4.1 through 4.4 received in DHCPv4 Access Network Identifier
or Relay Agent Information option it MAY use it for address pool
selection policy decisions as per its configured policy. DHCPv4
server MAY store this information along with the lease for logging
and audit purpose. DHCPv4 server MAY use the sub-options defined in
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sections 4.1 through section 4.4 inserted by the DHCPv4 client in
DHCPv4 Access Network Identifier option or by DHCPv4 relay agent in
Relay Agent Information option based on its configured policy.
If the DHCPv6 server receives the options defined in Section 5 and is
configured to store or use the options defined in Section 5, it
SHOULD look for the DHCPv6 Access Network identifier options in the
Relay-Forward DHCP message of the DHCPv6 relay agent(s) or from the
DHCPv6 client based on its configured policy.
9. IANA Considerations
This document defines DHCPv4 Access Network Identifier option which
requires assignment of DHCPv4 option code TBD1 assigned from "BOOTP
Vendor Extensions and DHCP Options" registry <http://www.iana.org/
assignments/bootp-dhcp-parameters/bootp-dhcp-parameters.xml>, as
specified in [RFC2939].
IANA is requested to assign Sub-option codes for the following DHCPv4
Sub-options from the "DHCP Relay Agent Sub-Option Codes"
+================+========================================+
| SUBOPTION CODE | SUBOPTION DESCRIPTION |
+================+========================================+
| <IANA-1> | Access Technology Type Suboption |
+=========================================================+
| <IANA-2> | Access Network Name Suboption |
+=========================================================+
| <IANA-3> | Access Point Name Suboption |
+=========================================================+
| <IANA-4> | Access Point BSSID Sub-option |
+=========================================================+
| <IANA-5> | Operator-Identifier Sub-option |
+=========================================================+
| <IANA-6> | Operator-Realm Sub-option |
+=========================================================+
IANA is requested to assign option codes for the following DHCPv6
options from the "Option Codes registry for DHCPv6" registry <http://
www.iana.org/assignments/dhcpv6-parameters/dhcpv6-parameters.xml>, as
specified.
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+================+========================================+
| OPTION CODE | OPTION DESCRIPTION |
+================+========================================+
| <IANA-7> | OPTION_ANI_ATT |
+=========================================================+
| <IANA-8> | OPTION_ANI_NETWORK_NAME |
+=========================================================+
| <IANA-9> | OPTION_ANI_AP_NAME |
+=========================================================+
| <IANA-10> | OPTION_ANI_AP_BSSID |
+=========================================================+
| <IANA-11> | OPTION_ANI_OPERATOR_ID |
+=========================================================+
| <IANA-12> | OPTION_ANI_OPERATOR_REALM |
+=========================================================+
10. Security Considerations
Since there is no privacy protection for DHCP messages, an
eavesdropper who can monitor the link between the DHCP server, relay
agent and client can discover access network information.
To minimize the unintended exposure of this information, this option
SHOULD be included by DHCP entities only when it is configured.
Where critical decisions might be based on the value of this option,
DHCP authentication as defined in "Authentication for DHCP Messages"
[RFC3118] and "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)"
[RFC3315] SHOULD be used to protect the integrity of the DHCP
options. Link-layer confidentiality and integrity protection may
also be employed to reduce the risk of disclosure and tampering.
Security issues related DHCPv6 are described in section 23 of
[RFC3315].
DHCP clients can fake its Access Network Identifier option values to
gain better service. DHCP Servers and Relay agents should be
configured with suitable policy to override or trust the access
network information received from DHCP clients.
It is possible for a rogue DHCP relay agent to insert or overwrite
with incorrect access network identifier options for malicious
purposes. A DHCP client can also pose as a rogue DHCP relay agent by
sending incorrect access network identifier options. While the
introduction of fraudulent DHCP relay agent information options can
be prevented by a perimeter defense that blocks these options unless
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the DHCP relay agent is trusted, a deeper defense using the
authentication suboption for DHCPv4 relay agent information option
[RFC4030] SHOULD be deployed as well. DHCP server administrators are
strongly advised to configure DHCP servers that use this option to
communicate with their relay agents using IPsec, as described in
Section 21.1 of [RFC3315].
11. Acknowledgements
The authors would like to thank Kim Kinnear, Ted Lemon, Gaurav
Halwasia, Bernie Volz, Tomek Mrugalski, Hidetoshi Yokota and Sheng
Jiang for their valuable inputs.
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol",
RFC 2131, March 1997.
[RFC3046] Patrick, M., "DHCP Relay Agent Information Option",
RFC 3046, January 2001.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003.
12.2. Informative References
[ANI] "Interoperability Specification (IOS) for High Rate Packet
Data (HRPD) Radio Access Network Interfaces with Session
Control in the Access Network, A.S0008-A v3.0",
October 2008.
[RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987.
[RFC2939] Droms, R., "Procedures and IANA Guidelines for Definition
of New DHCP Options and Message Types", BCP 43, RFC 2939,
September 2000.
[RFC3118] Droms, R. and W. Arbaugh, "Authentication for DHCP
Messages", RFC 3118, June 2001.
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[RFC4030] Stapp, M. and T. Lemon, "The Authentication Suboption for
the Dynamic Host Configuration Protocol (DHCP) Relay Agent
Option", RFC 4030, March 2005.
[RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.
[RFC5844] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
Mobile IPv6", RFC 5844, May 2010.
[RFC6757] Gundavelli, S., Korhonen, J., Grayson, M., Leung, K., and
R. Pazhyannur, "Access Network Identifier (ANI) Option for
Proxy Mobile IPv6", RFC 6757, October 2012.
[SMI] "PRIVATE ENTERPRISE NUMBERS, SMI Network Management
Private Enterprise Codes", February 2011.
[TS23003] "Numbering, addressing and identification", 2011.
[TS23203] "Policy and Charging Control Architecture", 2012.
[TS23402] "Architecture enhancements for non-3GPP accesses", 2012.
Authors' Addresses
Shwetha Bhandari
Cisco Systems
Cessna Business Park, Sarjapura Marathalli Outer Ring Road
Bangalore, KARNATAKA 560 087
India
Phone: +91 80 4426 0474
Email: shwethab@cisco.com
Sri Gundavelli
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134
USA
Email: sgundave@cisco.com
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Jouni Korhonen
Renesas Mobile
Linnoitustie 6
FIN-02600 Espoo,
Finland
Phone:
Email: jouni.nospam@gmail.com
Mark Grayson
Cisco Systems
11 New Square Park
Bedfont Lakes, FELTHAM TW14 8HA
ENGLAND
Email: mgrayson@cisco.com
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