| Network Working Group | M. Boucadair |
| Internet-Draft | Orange |
| Intended status: Standards Track | T. Reddy |
| Expires: September 29, 2019 | McAfee |
| P. Patil | |
| Cisco | |
| March 28, 2019 |
Distributed-Denial-of-Service Open Threat Signaling (DOTS) Server Discovery
draft-ietf-dots-server-discovery-00
It may not be possible for a network to determine the cause for an attack, but instead just realize that some resources seem to be under attack. To fill that gap, Distributed-Denial-of-Service Open Threat Signaling (DOTS) allows a network to inform a DOTS server that it is under a potential attack so that appropriate mitigation actions are undertaken.
This document specifies mechanisms to configure nodes with DOTS servers.
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 September 29, 2019.
Copyright (c) 2019 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 extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
In many deployments, it may not be possible for a network to determine the cause for a distributed Denial-of-Service (DoS) attack [RFC4732], but instead just realize that some resources seem to be under attack. To fill that gap, the IETF is specifying an architecture, called DDoS Open Threat Signaling (DOTS) [I-D.ietf-dots-architecture], in which a DOTS client can inform a DOTS server that the network is under a potential attack and that appropriate mitigation actions are required. Indeed, because the lack of a common method to coordinate a real-time response among involved actors and network domains inhibits the effectiveness of DDoS attack mitigation, DOTS protocol is meant to carry requests for DDoS attack mitigation, thereby reducing the impact of an attack and leading to more efficient defensive actions. [I-D.ietf-dots-use-cases] identifies a set of scenarios for DOTS.
The basic high-level DOTS architecture is illustrated in Figure 1 ([I-D.ietf-dots-architecture]):
+-----------+ +-------------+
| Mitigator | ~~~~~~~~~~ | DOTS Server |
+-----------+ +-------------+
|
|
|
+---------------+ +-------------+
| Attack Target | ~~~~~~ | DOTS Client |
+---------------+ +-------------+
Figure 1: Basic DOTS Architecture
[I-D.ietf-dots-architecture] specifies that the DOTS client may be provided with a list of DOTS servers; each associated with one or more IP addresses. These addresses may or may not be of the same address family. The DOTS client establishes one or more DOTS sessions by connecting to the provided DOTS server addresses. The logic for connecting to one or multiple IP addresses is out of scope of this document.
This document specifies methods for DOTS clients to discover their DOTS server(s). The rationale for specifying multiple discovery mechanisms is discussed in Section 4.
Considerations for the selection of DOTS server(s) by multi-homed DOTS clients is out of scope; the reader should refer to [I-D.boucadair-dots-multihoming] for more details.
Likewise, happy eyeballs considerations for DOTS are out of scope. The reader should refer to Section 4 of [I-D.ietf-dots-signal-channel].
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.
This document makes use of the following terms:
Furthermore, the reader should be familiar with other terms defined in [I-D.ietf-dots-architecture] and [RFC3958].
It is tempting to specify one single discovery mechanism for DOTS. Nevertheless, the analysis of the various use cases sketched in [I-D.ietf-dots-use-cases] reveals that it is unlikely that one single discovery method can be suitable for all the sample deployments (Table 1). Concretely:
| Use Case | Requires a CPE | The Network Provider is also the DDoS Mitigation Provider |
|---|---|---|
| End-customer with single or multiple upstream transit provider(s) offering DDoS mitigation services | Yes (Intelligent DDoS mitigation system (IDMS) acting as a DOTS client may be co-located on the CPE) | Yes |
| End-customer with an overlay DDoS mitigation managed security service provider (MSSP) | Yes (DDOS Detector acting as a DOTS client may be co-located on the CPE) | No |
| End-customer operating an application or service with an integrated DOTS client | Yes (CPE may act as a DOTS gateway) | Yes/No |
| End-customer operating a CPE network infrastructure device with an integrated DOTS client | Yes (CPE acts as a DOTS client) | Yes |
| Suppression of outbound DDoS traffic originating from a consumer broadband access network | Yes (CPE acts as a DOTS server) | Yes |
| DDoS Orchestration | No | N/A |
Consequently, this document describes the following mechanisms for discovery:
A key point in the deployment of DOTS is the ability of network operators to be able to configure DOTS clients with the correct server information consistently. To accomplish this, operators will need a consistent set of ways in which DOTS clients can discover this information, and a consistent priority among these options. If some devices prefer manual configuration over DNS discovery, while others prefer DNS discovery over manual configuration, the result will be a process of "whack-a-mole", where the operator must find devices that are using the wrong DOTS server, determine how to ensure the devices are configured properly, and then reconfigure the device through the preferred method.
All DOTS clients MUST support at least one of the four mechanisms below to determine a DOTS server list. All DOTS clients SHOULD implement all four, or as many as are practical for any specific device, of these ways to discover DOTS servers, in order to facilitate the deployment of DOTS in large scale environments:
Some of these mechanisms imply the use of DNS to resolve the IP address of the DOTS server, while others imply the IP address of the relevant DOTS server is obtained directly. Implementation options may vary on a per device basis, as some devices may not have DNS capabilities and/or proper configuration.
Clients will prefer information received from the discovery methods in the order listed.
On hosts with more than one interface or address family (IPv4/v6), the DOTS server discovery procedure has to be performed for each combination of interface and address family. A client MAY choose to perform the discovery procedure only for a desired interface/address combination if the client does not wish to discover a DOTS server for all combinations of interface and address family.
The above procedure MUST also be followed by a DOTS gateway.
Once the DOTS client has retrieved client's DNS domain or discovered the DOTS server name that needs to be resolved, an S-NAPTR lookup with 'DOTS' application service and the desired protocol tag is made to obtain information necessary to connect to the authoritative DOTS server within the given domain.
This specification defines "DOTS" as an application service tag (Section 12.3.1) and "signal.udp" (Section 12.3.2), "signal.tcp" (Section 12.3.3), and "data.tcp" (Section 12.3.4) as application protocol tags.
In the example below, for domain 'example.net', the resolution
algorithm will result in IP address(es), port, tag and protocol tuples as
follows:
example.net.
IN NAPTR 100 10 "" DOTS:signal.udp "" signal.example.net.
IN NAPTR 200 10 "" DOTS:signal.tcp "" signal.example.net.
IN NAPTR 300 10 "" DOTS:data.tcp "" data.example.net.
signal.example.net.
IN NAPTR 100 10 S DOTS:signal.udp "" _dots._signal._udp.example.net.
IN NAPTR 200 10 S DOTS:signal.tcp "" _dots._signal._tcp.example.net.
data.example.net.
IN NAPTR 100 10 S DOTS:data.tcp "" _dots._data._tcp.example.net.
_dots._signal._udp.example.net.
IN SRV 0 0 5000 a.example.net.
_dots._signal._tcp.example.net.
IN SRV 0 0 5001 a.example.net.
_dots._data._tcp.example.net.
IN SRV 0 0 5002 a.example.net.
a.example.net.
IN AAAA 2001:db8::1
+-------+----------+-------------+------+--------+
| Order | Protocol | IP address | Port | Tag |
+-------+----------+-------------+------+--------+
| 1 | UDP | 2001:db8::1 | 5000 | Signal |
| 2 | TCP | 2001:db8::1 | 5001 | Signal |
| 3 | TCP | 2001:db8::1 | 5002 | Data |
+-------+----------+-------------+------+--------+
If no DOTS-specific S-NAPTR records can be retrieved, the discovery procedure fails for this domain name (and the corresponding interface and IP protocol version). If more domain names are known, the discovery procedure MAY perform the corresponding S-NAPTR lookups immediately. However, before retrying a lookup that has failed, a DOTS client MUST wait a time period that is appropriate for the encountered error (e.g., NXDOMAIN, timeout, etc.).
This mechanism is performed in two steps:
A DOTS client has to determine the domain in which it is located. The following section describes the means to obtain the domain name from DHCP. Other means of retrieving domain names may be used, which are outside the scope of this document, e.g., local configuration.
Implementations MAY allow the user to specify a default name that is used, if no specific name has been configured.
DHCP can be used to determine the domain name related to an interface's point of network attachment. Network operators may provide the domain name to be used for service discovery within an access network using DHCP. Sections 3.2 and 3.3 of [RFC5986] define DHCP IPv4 and IPv6 access network domain name options, OPTION_V4_ACCESS_DOMAIN and OPTION_V6_ACCESS_DOMAIN respectively, to identify a domain name that is suitable for service discovery within the access network.
For IPv4, the discovery procedure MUST request the access network domain name option in a Parameter Request List option, as described in [RFC2131]. [RFC2132] defines the DHCP IPv4 domain name option; while this option is less suitable, a client MAY request for it if the access network domain name defined in [RFC5986] is not available.
For IPv6, the discovery procedure MUST request for the access network domain name option in an Options Request Option (ORO) within an Information-request message, as described in [RFC3315].
If neither option can be retrieved the procedure fails for this interface. If a result can be retrieved it will be used as an input for S-NAPTR resolution discussed in Section 6.
DNS-based Service Discovery (DNS-SD) [RFC6763] and Multicast DNS (mDNS) [RFC6762] provide generic solutions for discovering services. DNS-SD/mDNS define a set of naming rules for certain DNS record types that they use for advertising and discovering services.
Section 4.1 of [RFC6763] specifies that a service instance name in DNS-SD has the following structure:
<Instance> . <Service> . <Domain>
The <Domain> portion specifies the DNS sub-domain where the service instance is registered. It may be "local.", indicating the mDNS local domain, or it may be a conventional domain name such as "example.com.".
The <Service> portion of the DOTS service instance name MUST be "_dots._signal._udp" or "_dots._signal._tcp" or "_dots._data._tcp".
A DOTS client can proactively discover DOTS servers being advertised in the site by multicasting a PTR query to one or all of the following:
A DOTS server can send out gratuitous multicast DNS answer packets whenever it starts up, wakes from sleep, or detects a change in network configuration. DOTS clients receive these gratuitous packets and cache information contained in it.
As reported in Section 1.7.2 of [RFC6125]:
In order to allow for PKIX-based authentication between a DOTS client and server while accommodating for the current best practices for issuing certificates, this document allows for configuring names to DOTS clients. These names can be used for two purposes: to retrieve the list of IP addresses of a DOTS server or to be presented as a reference identifier for authentication purposes.
Defining the option to include a list of IP addresses would avoid a dependency on an underlying name resolution, but that design requires to also supply a name for PKIX-based authentication purposes.
The DHCPv6 DOTS option is used to configure a name of the DOTS server. The format of this option is shown in Figure 2.
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_V6_DOTS | Option-length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | dots-server-name (FQDN) | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: DHCPv6 DOTS Reference Identifier option
Figure 2 are as follows:
Figure 3. This example conveys the FQDN "dots.example.com.".
+------+------+------+------+------+------+------+------+------+
| 0x04 | d | o | t | s | 0x07 | e | x | a |
+------+------+------+------+------+------+------+------+------+
| m | p | l | e | 0x03 | c | o | m | 0x00 |
+------+------+------+------+------+------+------+------+------+
Figure 3: An example of the dots-server-name encoding
The DHCPv6 DOTS option can be used to configure a list of IPv6 addresses of a DOTS server. The format of this option is shown in Figure 4.
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_V6_DOTS | Option-length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | DOTS ipv6-address | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | DOTS ipv6-address | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: DHCPv6 DOTS Address option
Figure 4 are as follows:
DHCP clients MAY request options OPTION_V6_DOTS_RI and OPTION_V6_DOTS_ADDRESS, as defined in [RFC3315], Sections 17.1.1, 18.1.1, 18.1.3, 18.1.4, 18.1.5, and 22.7. As a convenience to the reader, it is mentioned here that the DHCP client includes the requested option codes in the Option Request Option.
If the DHCP client receives more than one instance of OPTION_V6_DOTS_RI (resp. OPTION_V6_DOTS_ADDRESS) option, it MUST use only the first instance of that option.
If the DHCP client receives both OPTION_V6_DOTS_RI and OPTION_V6_DOTS_ADDRESS, the content of OPTION_V6_DOTS_RI is used as reference identifier for authentication purposes (e.g., PKIX [RFC6125]), while the addresses included in OPTION_V6_DOTS_ADDRESS are used to reach the DOTS server. In other words, the name conveyed in OPTION_V6_DOTS_RI MUST NOT be passed to underlying resolution library in the presence of OPTION_V6_DOTS_ADDRESS in a response.
If the DHCP client receives OPTION_V6_DOTS_RI only, but OPTION_V6_DOTS_RI option contains more than one name, as distinguished by the presence of multiple root labels, the DHCP client MUST use only the first name. Once the name is validated (Section 8 of [RFC3315]), the name is passed to a name resolution library. Moreover, that name is also used as a reference identifier for authentication purposes.
If the DHCP client receives OPTION_V6_DOTS_ADDRESS only, the address(es) included in OPTION_V6_DOTS_ADDRESS is used to reach the DOTS server. In addition, these addresses can be used as identifiers for authentication.
The DHCPv4 DOTS option is used to configure a name of the DOTS server. The format of this option is illustrated in Figure 5.
Code Length DOTS server name
+-----+-----+-----+-----+-----+-----+-----+--
| TBA | n | s1 | s2 | s3 | s4 | s5 | ...
+-----+-----+-----+-----+-----+-----+-----+--
The values s1, s2, s3, etc. represent the domain name labels in the
domain name encoding.
Figure 5: DHCPv4 DOTS Reference Identifier option
The fields of the option shown in Figure 5 are as follows:
The DHCPv4 DOTS option can be used to configure a list of IPv4 addresses of a DOTS server. The format of this option is illustrated in Figure 6.
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Code | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | List-Length | List of | +-+-+-+-+-+-+-+-+ DOTS | / IPv4 Addresses / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ --- | List-Length | List of | | +-+-+-+-+-+-+-+-+ DOTS | | / IPv4 Addresses / | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | . ... . optional +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | List-Length | List of | | +-+-+-+-+-+-+-+-+ DOTS | | / IPv4 Addresses / | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ---
Figure 6: DHCPv4 DOTS Address option
0 8 16 24 32 40 48
+-----+-----+-----+-----+-----+-----+--
| a1 | a2 | a3 | a4 | a1 | a2 | ...
+-----+-----+-----+-----+-----+-----+--
IPv4 Address 1 IPv4 Address 2 ...
The fields of the option shown in Figure 6 are as follows:
This format assumes that an IPv4 address is encoded as a1.a2.a3.a4.
Figure 7: Format of the List of DOTS IPv4 Addresses
[RFC3396] MUST be used if OPTION_V4_DOTS exceeds the maximum DHCPv4 option size of 255 octets.
To discover a DOTS server, the DHCPv4 client MUST include both OPTION_V4_DOTS_RI and OPTION_V4_DOTS_ADDRESS in a Parameter Request List Option [RFC2132].
If the DHCP client receives more than one instance of OPTION_V4_DOTS_RI (resp. OPTION_V4_DOTS_ADDRESS) option, it MUST use only the first instance of that option.
If the DHCP client receives both OPTION_V4_DOTS_RI and OPTION_V4_DOTS_ADDRESS, the content of OPTION_V6_DOTS_RI is used as reference identifier for authentication purposes, while the addresses included in OPTION_V4_DOTS_ADDRESS are used to reach the DOTS server. In other words, the name conveyed in OPTION_V4_DOTS_RI MUST NOT be passed to underlying resolution library in the presence of OPTION_V4_DOTS_ADDRESS in a response.
If the DHCP client receives OPTION_V4_DOTS_RI only, but OPTION_V4_DOTS_RI option contains more than one name, as distinguished by the presence of multiple root labels, the DHCP client MUST use only the first name. Once the name is validated (Section 8 of [RFC3315]), the name is passed to a name resolution library. Moreover, that name is also used as a reference identifier for authentication purposes.
If the DHCP client receives OPTION_V4_DOTS_ADDRESS only, the address(es) included in OPTION_V4_DOTS_ADDRESS is used to reach the DOTS server. In addition, these addresses can be used as identifiers for authentication.
IP anycast can also be used for DOTS service discovery. A packet sent to an anycast address is delivered to the 'topologically nearest' network interface with the anycast address.
When a DOTS client requires DOTS services, it attempts to establish a signaling session with the assigned anycast address(es) defined in Sections 12.4 and 12.5. A DOTS server, that receives a DOTS request with an anycast address, SHOULD redirect the DOTS client to the appropriate DOTS unicast server(s) using the mechanism described in Section 5.5 of [I-D.ietf-dots-signal-channel], unless it is configured otherwise. Indeed, a DOTS server SHOULD be configurable to maintain all DOTS communications using anycast. DOTS redirect is not made mandatory because the use of anycast is not problematic for some deployment scenarios such as an enterprise network deploying one single DOTS gateway connected to one single network provider.
[I-D.boucadair-dots-multihoming] identifies a set of deployment schemes in which the use of anycast is not recommended.
DOTS-related security considerations are discussed in Section 4 of [I-D.ietf-dots-architecture] is to be considered. DOTS agents must authenticate each other using (D)TLS before a DOTS session is considered valid.
If the DOTS client is explicitly configured with DOTS server(s) then the DOTS client can also be explicitly configured with credentials to authenticate the DOTS server.
The CPE device acting as a DOTS client MAY use Bootstrapping Remote Secure Key Infrastructures (BRSKI) discussed in [I-D.ietf-anima-bootstrapping-keyinfra] to automatically bootstrap using the vendor installed X.509 certificate, in combination with a domain registrar provided by the upstream transit provider and vendor's authorizing service. The CPE device authenticates to the upstream transit provider using the vendor installed X.509 certificate and the upstream transit provider validates the vendor installed certificate on the CPE device using the Manufacturer Authorized Signing Authority (MASA) service. If authentication is successful then the CPE device can request and get a voucher from the MASA service via the domain registrar. The voucher is signed by the MASA service and includes the upstream transit provider's trust anchor certificate. The CPE device validates the signed voucher using the manufacturer installed trust anchor associated with the vendor's selected MASA service and stores the upstream transit provider's trust anchor certificate. The CPE device then uses Enrollment over Secure Transport (EST) [RFC7030] for certificate enrollment (Section 3.8 in [I-D.ietf-anima-bootstrapping-keyinfra]). The DOTS client on the CPE device can authenticate to the DOTS server using the certificate provisioned by the EST server and the DOTS client can validate the DOTS server certificate using the upstream transit provider's trust anchor certificate it had received in the voucher.
The security considerations in [RFC2131] and [RFC3315] are to be considered.
The primary attack against the methods described in Section 7 is one that would lead to impersonation of a DOTS server. An attacker could attempt to compromise the S-NAPTR resolution. The use of mutual authentication makes it difficult to redirect a DOTS client to an illegitimate DOTS server.
Since DNS-SD is just a specification for how to name and use records in the existing DNS system, it has no specific additional security requirements over and above those that already apply to DNS queries and DNS updates. For DNS queries, DNS Security Extensions (DNSSEC) [RFC4033] SHOULD be used where the authenticity of information is important. For DNS updates, secure updates [RFC2136][RFC3007] SHOULD generally be used to control which clients have permission to update DNS records.
For mDNS, in addition to what has been described above, a principal security threat is a security threat inherent to IP multicast routing and any application that runs on it. A rogue system can advertise that it is a DOTS server. Discovery of such rogue systems as DOTS servers, in itself, is not a security threat if the DOTS client authenticates the discovered DOTS servers.
Anycast-related security considerations are discussed in [RFC4786] and [RFC7094].
IANA is requested to allocate the SRV service name of "_dots._signal" for DOTS signal channel over UDP or TCP, and the service name of "_dots._data" for DOTS data channel over TCP.
IANA is requested to assign the following new DHCPv6 Option Code in the registry maintained in http://www.iana.org/assignments/dhcpv6-parameters:
| Option Name | Value |
|---|---|
| OPTION_V6_DOTS_RI | TBA1 |
| OPTION_V6_DOTS_ADDRESS | TBA2 |
IANA is requested to assign the following new DHCPv4 Option Code in the registry maintained in http://www.iana.org/assignments/bootp-dhcp-parameters/:
| Option Name | Value | Data length | Meaning |
|---|---|---|---|
| OPTION_V4_DOTS_RI | TBA3 | Variable; the maximum length is 255 octets. | Includes the name of the DOTS server. |
| OPTION_V4_DOTS_ADDRESS | TBA4 | Variable; the minimum length is 5. | Includes one or multiple lists of DOTS IP addresses; each list is treated as a separate DOTS server. |
This document requests IANA to make the following allocations from the registry available at: https://www.iana.org/assignments/s-naptr-parameters/s-naptr-parameters.xhtml.
IANA has assigned a single IPv4 address from the 192.0.0.0/24 prefix and registered it in the "IANA IPv4 Special-Purpose Address Registry" [RFC6890].
+----------------------+-------------------------------------------+ | Attribute | Value | +----------------------+-------------------------------------------+ | Address Block | TBA | | Name | Distributed-Denial-of-Service Open Threat | | | Signaling (DOTS) Anycast | | RFC | <this document> | | Allocation Date | <date of approval of this document> | | Termination Date | N/A | | Source | True | | Destination | True | | Forwardable | True | | Global | True | | Reserved-by-Protocol | False | +----------------------+-------------------------------------------+
IANA has assigned a single IPv6 address from the 2001:0000::/23 prefix and registered it in the "IANA IPv6 Special-Purpose Address Registry" [RFC6890].
+----------------------+-------------------------------------------+ | Attribute | Value | +----------------------+-------------------------------------------+ | Address Block | TBA | | Name | Distributed-Denial-of-Service Open Threat | | | Signaling (DOTS) Anycast | | RFC | <this document> | | Allocation Date | <date of approval of this document> | | Termination Date | N/A | | Source | True | | Destination | True | | Forwardable | True | | Global | True | | Reserved-by-Protocol | False | +----------------------+-------------------------------------------+
Thanks to Brian Carpenter for the review of the BRSKI text.
Many thanks to Russ White for the review, comments, and text contribution.