--- 1/draft-ietf-dnssd-srp-01.txt 2019-07-08 17:20:41.783466583 -0700 +++ 2/draft-ietf-dnssd-srp-02.txt 2019-07-08 17:20:41.843468101 -0700 @@ -1,19 +1,19 @@ Internet Engineering Task Force S. Cheshire Internet-Draft Apple Inc. Intended status: Informational T. Lemon -Expires: September 12, 2019 Nibbhaya Consulting - March 11, 2019 +Expires: January 9, 2020 Nibbhaya Consulting + July 8, 2019 Service Registration Protocol for DNS-Based Service Discovery - draft-ietf-dnssd-srp-01 + draft-ietf-dnssd-srp-02 Abstract The Service Registration Protocol for DNS-Based Service Discovery uses the standard DNS Update mechanism to enable DNS-Based Service Discovery using only unicast packets. This makes it possible to deploy DNS Service Discovery without multicast, which greatly improves scalability and improves performance on networks where multicast service is not an optimal choice, particularly 802.11 (Wi-Fi) and 802.15.4 (IoT) networks. DNS-SD Service registration @@ -28,21 +28,21 @@ 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 12, 2019. + This Internet-Draft will expire on January 9, 2020. Copyright Notice 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 @@ -69,33 +69,33 @@ 2.4.2. SRP Server Behavior . . . . . . . . . . . . . . . . . 10 2.5. TTL Consistency . . . . . . . . . . . . . . . . . . . . . 12 2.6. Maintenance . . . . . . . . . . . . . . . . . . . . . . . 13 2.6.1. Cleaning up stale data . . . . . . . . . . . . . . . 13 2.6.2. Sleep Proxy . . . . . . . . . . . . . . . . . . . . . 14 3. Security Considerations . . . . . . . . . . . . . . . . . . . 15 3.1. Source Validation . . . . . . . . . . . . . . . . . . . . 15 3.2. SIG(0) signature validation . . . . . . . . . . . . . . . 16 3.3. Required Signature Algorithm . . . . . . . . . . . . . . 16 4. Privacy Considerations . . . . . . . . . . . . . . . . . . . 16 - 5. Delegation of 'services.arpa.' . . . . . . . . . . . . . . . 16 + 5. Delegation of 'service.arpa.' . . . . . . . . . . . . . . . . 17 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 - 6.1. Registration and Delegation of 'services.arpa' as a + 6.1. Registration and Delegation of 'service.arpa' as a Special-Use Domain Name . . . . . . . . . . . . . . . . . 17 6.2. 'dnssd-srp' Service Name . . . . . . . . . . . . . . . . 17 - 6.3. Anycast Address . . . . . . . . . . . . . . . . . . . . . 17 - 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 17 + 6.3. 'dnssd-srp-tls' Service Name . . . . . . . . . . . . . . 18 + 6.4. Anycast Address . . . . . . . . . . . . . . . . . . . . . 18 + 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 8.1. Normative References . . . . . . . . . . . . . . . . . . 18 8.2. Informative References . . . . . . . . . . . . . . . . . 19 - Appendix A. Sample BIND9 configuration for - default.services.arpa. . . . . . . . . . . . . . . . 20 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21 + Appendix A. Sample BIND9 configuration for default.service.arpa. 21 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 1. Introduction DNS-Based Service Discovery [RFC6763] is a component of Zero Configuration Networking [RFC6760] [ZC] [I-D.cheshire-dnssd-roadmap]. This document describes an enhancement to DNS-Based Service Discovery [RFC6763] that allows services to automatically register their services using the DNS protocol rather than using Multicast DNS [RFC6762] (mDNS). There is already a large installed base of DNS-SD @@ -169,38 +169,40 @@ Manual configuration of the registraton domain can be done either by querying the list of available registration zones ("r._dns-sd._udp") and allowing the user to select one from the UI, or by any other means appropriate to the particular use case being addressed. Full- featured devices construct the names of the SRV, TXT, and PTR records describing their service(s) as subdomains of the chosen service registration domain. For these names they then discover the zone apex of the closest enclosing DNS zone using SOA queries [I-D.ietf-dnssd-push]. Having discovered the enclosing DNS zone, they query for the "_dnssd-srp._tcp" SRV record to discover the - server to which they should send DNS updates. + server to which they should send DNS updates. Hosts that support SRP + updates using TLS use the "_dnssd-srp-tls._tcp" SRV record + instead. For devices designed for Constrained-Node Networks [RFC7228] some simplifications are available. Instead of being configured with (or discovering) the service registration domain, the (proposed) special- - use domain name [RFC6761] "default.services.arpa" is used. Instead - of learning the server to which they should send DNS updates, a fixed - IPv6 anycast address is used (value TBD). Anycasts are sent using - UDP unless TCP is required due to the size of the update. It is the - responsibility of a Constrained-Node Network supporting SRP to + use domain name (see [RFC6761]) "default.service.arpa" is used. + Instead of learning the server to which they should send DNS updates, + a fixed IPv6 anycast address is used (value TBD). Anycasts are sent + using UDP unless TCP is required due to the size of the update. It + is the responsibility of a Constrained-Node Network supporting SRP to provide appropriate anycast routing to deliver the DNS updates to the appropriate server. It is the responsibility of the SRP server supporting a Constrained-Node Network to handle the updates appropriately. In some network environments, updates may be accepted - directly into a local "default.services.arpa" zone, which has only + directly into a local "default.service.arpa" zone, which has only local visibility. In other network environments, updates for names - ending in "default.services.arpa" may be rewritten internally to - names with broader visibility. + ending in "default.service.arpa" may be rewritten internally to names + with broader visibility. The reason for these different assumptions is that Constrained-Node Networks generally require special egress support, and Anycast packets captured at the Constrained-Node Network egress can be assumed to have originated locally. Low-power devices that typically use Constrained-Node Networks may have very limited battery power. The additional DNS lookups required to discover an SRP server and then communicate with it will increase the power required to advertise a service; for low-power devices, the additional flexibility this provides does not justify the additional use of @@ -224,25 +226,24 @@ We refer to the DNS Update message sent by services using SRP as an SRP update. Three types of updates appear in an SRP update: Service Discovery records, Service Description records, and Host Description records. o Service Discovery records are one or more PTR RRs, mapping from the generic service type (or subtype) to the specific Service Instance Name. o Service Description records are exactly one SRV RR, exactly one - KEY RR, and one or more TXT RRs, both with the same name, the + KEY RR, and one or more TXT RRs, all with the same name, the Service Instance Name ([RFC6763] section 4.1). In principle Service Description records can include other record types, with the same Service Instance Name, though in practice they rarely do. - The Service Instance Name MUST be referenced by one or more Service Discovery PTR records, unless it is a placeholder service registration for an intentionally non-discoverable service name. o The Host Description records for a service are a KEY RR, used to claim exclusive ownership of the service registration, and one or more RRs of type A or AAAA, giving the IPv4 or IPv6 address(es) of the host where the service resides. RFC 6763 describes the details of what each of these types of updates @@ -257,123 +258,122 @@ 2.2. Where to publish it Multicast DNS uses a single namespace, ".local", which is valid on the local link. This convenience is not available for DNS-SD using the DNS protocol: services must exist in some specific unicast namespace. As described above, full-featured devices are responsible for knowing in what domain they should register their services. Devices made for Constrained-Node Networks register in the (proposed) special use - domain name [RFC6761] "default.services.arpa", and let the SRP server + domain name [RFC6761] "default.service.arpa", and let the SRP server handle rewriting that to a different domain if necessary. 2.3. How to publish it It is possible to issue a DNS Update that does several things at once; this means that it's possible to do all the work of adding a - PTR resource record to the PTR RRset on the Service Name if it - already exists, or creating one if it doesn't, and creating or - updating the Service Instance Name and Host Description in a single - transaction. + PTR resource record to the PTR RRset on the Service Name, and + creating or updating the Service Instance Name and Host Description, + in a single transaction. - An SRP update is therefore implemented as a single DNS Update message - that contains a service's Service Discovery records, Service - Description records, and Host Description records. + An SRP update takes advantage of this: it is implemented as a single + DNS Update message that contains a service's Service Discovery + records, Service Description records, and Host Description records. Updates done according to this specification are somewhat different than regular DNS Updates as defined in RFC2136. RFC2136 uses a fairly heavyweight process for updating: you might first attempt to add a name if it doesn't exist; if that fails, then in a second message you might update the name if it does exist but matches certain preconditions. Because the registration protocol uses a single transaction, some of this adaptability is lost. In order to allow updates to happen in a single transaction, SRP - updates do not include update constraints. The constraints specified - in Section 2.4.2 are implicit in the processing of SRP updates, and - so there is no need for the service sending the SRP update to put in - any explicit constraints. + updates do not include update prerequisites. The specified in + Section 2.4.2 are implicit in the processing of SRP updates, and so + there is no need for the service sending the SRP update to put in any + explicit prerequisites. 2.3.1. How DNS-SD Service Registration differs from standard RFC2136 DNS Update DNS-SD Service Registration is based on standard RFC2136 DNS Update, with some differences: o It implements first-come first-served name allocation, protected using SIG(0) [RFC2931]. o It enforces policy about what updates are allowed. - o It optionally performs rewriting of "default.services.arpa" to - some other domain. + o It optionally performs rewriting of "default.service.arpa" to some + other domain. o It optionally performs automatic population of the address-to-name reverse mapping domains. o An SRP server is not required to implement general DNS Update prerequsite processing. o Simplified clients are allowed to send updates to an anycast - address, for names ending in "default.services.arpa" + address, for names ending in "default.service.arpa" 2.3.2. Testing using standard RFC2136-compliant servers It may be useful to set up a DNS server for testing that does not implement SRP. This can be done by configuring the server to listen on the anycast address, or advertising it in the - _dnssd-srp._tcp. SRV record. It must be configured to be - authoritative for "default.services.arpa", and to accept updates from - hosts on local networks for names under "default.services.arpa" - without authentication, since such servers will not have support for - FCFS authentication Section 2.4.1. + _dnssd-srp._tcp. SRV and _dnssd-srp-tls._tcp. record. It + must be configured to be authoritative for "default.service.arpa", + and to accept updates from hosts on local networks for names under + "default.service.arpa" without authentication, since such servers + will not have support for FCFS authentication Section 2.4.1. A server configured in this way will be able to successfully accept and process SRP updates from services that send SRP updates. - However, no constraints will be applied, and this means that the test - server will accept internally inconsistent SRP updates, and will not - stop two SRP updates, sent by different services, that claim the same - name(s), from overwriting each other. + However, no prerequisites will be applied, and this means that the + test server will accept internally inconsistent SRP updates, and will + not stop two SRP updates, sent by different services, that claim the + same name(s), from overwriting each other. Since SRP updates are signed with keys, validation of the SIG(0) algorithm used by the client can be done by manually installing the client public key on the DNS server that will be receiving the updates. The key can then be used to authenticate the client, and can be used as a requirement for the update. An example configuration for testing SRP using BIND 9 is given in Appendix A. 2.3.3. How to allow services to update standard RFC2136-compliant servers Ordinarily SRP updates will fail when sent to an RFC 2136-compliant server that does not implement SRP because the zone being updated is - "default.services.arpa", and no DNS server that is not an SRP server + "default.service.arpa", and no DNS server that is not an SRP server should normally be configured to be authoritative for - "default.services.arpa". Therefore, a service that sends an SRP + "default.service.arpa". Therefore, a service that sends an SRP update can tell that the receiving server does not support SRP, but does support RFC2136, because the RCODE will either be NOTZONE, NOTAUTH or REFUSED, or because there is no response to the update request (when using the anycast address) In this case a service MAY attempt to register itself using regular RFC2136 DNS updates. To do so, it must discover the default registration zone and the DNS server designated to receive updates - for that zone, as described earlier using the _dns-update._udp SRV + for that zone, as described earlier, using the _dns-update._udp SRV record. It can then make the update using the port and host pointed - to by the SRV record, and should use appropriate constraints to avoid - overwriting competing records. Such updates are out of scope for - SRP, and a service that implements SRP MUST first attempt to use SRP - to register itself, and should only attempt to use RFC2136 backwards - compatibility if that fails. Although the owner name for the SRV - record specifies the UDP protocol for updates, it is also possible to - use TCP, when the update is too large. + to by the SRV record, and should use appropriate prerequisites to + avoid overwriting competing records. Such updates are out of scope + for SRP, and a service that implements SRP MUST first attempt to use + SRP to register itself, and should only attempt to use RFC2136 + backwards compatibility if that fails. Although the owner name for + the SRV record specifies the UDP protocol for updates, it is also + possible to use TCP, and TCP should be required to prevent spoofing. 2.4. How to secure it Traditional DNS update is secured using the TSIG protocol, which uses a secret key shared between the client (which issues the update) and the server (which authenticates it). This model does not work for automatic service registration. The goal of securing the DNS-SD Registration Protocol is to provide the best possible security given the constraint that service @@ -403,21 +403,21 @@ pair MUST be unique to the device. When sending DNS updates, the service includes a KEY record containing the public portion of the key in each Host Description update and each Service Description update. Each KEY record MUST contain the same public key. The update is signed using SIG(0), using the private key that corresponds to the public key in the KEY record. The lifetimes of the records in the update is set using the EDNS(0) Update Lease option [I-D.sekar-dns-ul]. - The KEY record in service description updates MAY be omitted for + The KEY record in Service Description updates MAY be omitted for brevity; if it is omitted, the SRP server MUST behave as if the same KEY record that is given for the Host Description is also given for each Service Description for which no KEY record is provided. Omitted KEY records are not used when computing the SIG(0) signature. The lifetime of the DNS-SD PTR, SRV, A, AAAA and TXT records [RFC6763] uses the LEASE field of the Update Lease option, and is typically set to two hours. This means that if a device is disconnected from the network, it does not appear in the user interfaces of devices looking for services of that type for too long. @@ -442,20 +442,25 @@ RFC2136. The SRP server checks each update in the SRP update to see that it contains a Service Discovery update, a Service Description update, and a Host Description update. Order matters in DNS updates. Specifically, deletes must precede adds for records that the deletes would affect; otherwise the add will have no effect. This is the only ordering constraint; aside from this constraint, updates may appear in whatever order is convenient when constructing the update. + Because the SRP update is a DNS update, it MUST contain a single + question that indicates the zone to be updated. Every delete and + update in an SRP update MUST be within the zone that is specified for + the SRP Update. + An update is a Service Discovery update if it contains o exactly one RRset update, o which is for a PTR RR, o which points to a Service Instance Name o for which an update is present in the SRP update. o Service Discovery updates do not contain any deletes, and do not contain any other updates. An update is a Service Description update if, for the appropriate @@ -481,25 +486,25 @@ public key corresponding to the private key that was used to sign the message, o there is a Service Instance Name update in the SRP update that updates an SRV RR so that it points to the hostname being updated by this update. o Host Description updates do not update any other records. An SRP update MUST include at least one Service Discovery update, at least one Service Description update, and exactly one Host Description update. An update message that does not is not an SRP - update. An update message that contains any other updates, or any - update constraints, is not an SRP update. Such messages should - either be processed as regular RFC2136 updates, including access - control checks and constraint checks, if supported, or else rejected - with RCODE=REFUSED. + update. An update message that contains any other updates, any other + deletes, or any update prerequisites, is not an SRP update. Such + messages should either be processed as regular RFC2136 updates, + including access control checks and constraint checks, if supported, + or else rejected with RCODE=REFUSED. Note that if the definitions of each of these update types are followed carefully, this means that many things that look very much like SRP updates nevertheless are not. For example, a DNS update that contains an update to a Service Name and an update to a Service Instance Name, where the Service Name does not reference the Service Instance Name, is not a valid SRP update message, but may be a valid RFC2136 update. Assuming that an update message has been validated with these @@ -522,26 +527,29 @@ KEY record updates omitted from Service Description update are processed as if they had been explicitly present: every Service Description that is updated MUST, after the update, have a KEY RR, and it must be the same KEY RR that is present in the Host Description to which the Service Description refers. The status that is returned depends on the result of processing the update, and can be either SUCCESS or SERVFAIL: all other possible outcomes should already have been accounted for when applying the - constraints. + constraints that qualify the update as an SRP Update. The server MAY add a Reverse Mapping that corresponds to the Host Description. This is not required because the Reverse Mapping serves no protocol function, but it may be useful for debugging, e.g. in - annotating network packet traces or logs. + annotating network packet traces or logs. In order for the server to + add a reverse mapping update, it must be authoritative for the zone + or have credentials to do the update. The client MAY also do a + reverse mapping update if it has credentials to do so. The server MAY apply additional criteria when accepting updates. In some networks, it may be possible to do out-of-band registration of keys, and only accept updates from pre-registered keys. In this case, an update for a key that has not been registered should be rejected with the REFUSED RCODE. There are at least two benefits to doing this rather than simply using normal SIG(0) DNS updates. First, the same registration protocol can be used in both cases, so both use cases can be @@ -745,58 +753,82 @@ For validation, SRP Servers MUST implement the ECDSAP256SHA256 signature algorithm. SRP servers SHOULD implement the algorithms specified in [I-D.ietf-dnsop-algorithm-update] section 3.1, in the validation column of the table, starting with algorithm number 13. SRP clients MUST NOT assume that any algorithm numbered lower than 13 is available for use in validating SIG(0) signatures. 4. Privacy Considerations -5. Delegation of 'services.arpa.' + Because DNSSD SRP updates can be sent off-link, the privacy + implications of SRP are different than for multicast DNS responses. + Host implementations that are using TCP SHOULD also use TLS if + available. Server implementations MUST offer TLS support. The use + of TLS with DNS is described in [RFC7858] and [RFC8310]. + + Hosts that implement TLS support SHOULD NOT fall back to TCP; since + servers are required to support TLS, it is entirely up to the host + implementation whether to use it. + +5. Delegation of 'service.arpa.' In order to be fully functional, there must be a delegation of - 'services.arpa.' in the '.arpa.' zone [RFC3172]. This delegation + 'service.arpa.' in the '.arpa.' zone [RFC3172]. This delegation should be set up as was done for 'home.arpa', as a result of the specification in [RFC8375]Section 7. 6. IANA Considerations -6.1. Registration and Delegation of 'services.arpa' as a Special-Use +6.1. Registration and Delegation of 'service.arpa' as a Special-Use Domain Name - IANA is requested to record the domain name 'services.arpa.' in the + IANA is requested to record the domain name 'service.arpa.' in the Special-Use Domain Names registry [SUDN]. IANA is requested, with the approval of IAB, to implement the delegation requested in Section 5. IANA is further requested to add a new entry to the "Transport- Independent Locally-Served Zones" subregistry of the the "Locally- Served DNS Zones" registry[LSDZ]. The entry will be for the domain - 'services.arpa.' with the description "DNS-SD Registration Protocol + 'service.arpa.' with the description "DNS-SD Registration Protocol Special-Use Domain", listing this document as the reference. 6.2. 'dnssd-srp' Service Name IANA is also requested to add a new entry to the Service Names and Port Numbers registry for dnssd-srp with a transport type of tcp. No port number is to be assigned. The reference should be to this document, and the Assignee and Contact information should reference the authors of this document. The Description should be as follows: Availability of DNS Service Discovery Service Registration Protocol Service for a given domain is advertised using the "_dnssd-srp._tcp.." SRV record gives the target host and port where DNSSD Service Registration Service is provided for the named domain. -6.3. Anycast Address +6.3. 'dnssd-srp-tls' Service Name + + IANA is also requested to add a new entry to the Service Names and + Port Numbers registry for dnssd-srp with a transport type of tcp. No + port number is to be assigned. The reference should be to this + document, and the Assignee and Contact information should reference + the authors of this document. The Description should be as follows: + + Availability of DNS Service Discovery Service Registration Protocol + Service for a given domain over TLS is advertised using the + "_dnssd-srp-tls._tcp.." SRV record gives the target host and + port where DNSSD Service Registration Service is provided for the + named domain. + +6.4. Anycast Address IANA is requested to allocate an IPv6 Anycast address from the IPv6 Special-Purpose Address Registry, similar to the Port Control Protocol anycast address, 2001:1::1. This address is referred to within the document as TBD1, and the document should be updated to reflect the address that was allocated. 7. Acknowledgments Thanks to Toke Hoeiland-Joergensen for a thorough technical review, @@ -831,22 +863,21 @@ RFC 8106, DOI 10.17487/RFC8106, March 2017, . [RFC8375] Pfister, P. and T. Lemon, "Special-Use Domain 'home.arpa.'", RFC 8375, DOI 10.17487/RFC8375, May 2018, . [I-D.ietf-dnsop-algorithm-update] Wouters, P. and O. Sury, "Algorithm Implementation Requirements and Usage Guidance for DNSSEC", draft-ietf- - dnsop-algorithm-update-06 (work in progress), February - 2019. + dnsop-algorithm-update-10 (work in progress), April 2019. [SUDN] "Special-Use Domain Names Registry", July 2012, . [LSDZ] "Locally-Served DNS Zones Registry", July 2011, . 8.2. Informative References @@ -895,76 +926,86 @@ [RFC6762] Cheshire, S. and M. Krochmal, "Multicast DNS", RFC 6762, DOI 10.17487/RFC6762, February 2013, . [RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for Constrained-Node Networks", RFC 7228, DOI 10.17487/RFC7228, May 2014, . + [RFC7858] Hu, Z., Zhu, L., Heidemann, J., Mankin, A., Wessels, D., + and P. Hoffman, "Specification for DNS over Transport + Layer Security (TLS)", RFC 7858, DOI 10.17487/RFC7858, May + 2016, . + + [RFC8310] Dickinson, S., Gillmor, D., and T. Reddy, "Usage Profiles + for DNS over TLS and DNS over DTLS", RFC 8310, + DOI 10.17487/RFC8310, March 2018, + . + [I-D.ietf-dnssd-hybrid] Cheshire, S., "Discovery Proxy for Multicast DNS-Based - Service Discovery", draft-ietf-dnssd-hybrid-08 (work in - progress), March 2018. + Service Discovery", draft-ietf-dnssd-hybrid-10 (work in + progress), March 2019. [I-D.ietf-dnssd-push] Pusateri, T. and S. Cheshire, "DNS Push Notifications", - draft-ietf-dnssd-push-17 (work in progress), March 2019. + draft-ietf-dnssd-push-21 (work in progress), July 2019. [I-D.cheshire-dnssd-roadmap] Cheshire, S., "Service Discovery Road Map", draft- cheshire-dnssd-roadmap-03 (work in progress), October 2018. [I-D.cheshire-edns0-owner-option] Cheshire, S. and M. Krochmal, "EDNS0 OWNER Option", draft- cheshire-edns0-owner-option-01 (work in progress), July 2017. [ZC] Cheshire, S. and D. Steinberg, "Zero Configuration Networking: The Definitive Guide", O'Reilly Media, Inc. , ISBN 0-596-10100-7, December 2005. -Appendix A. Sample BIND9 configuration for default.services.arpa. +Appendix A. Sample BIND9 configuration for default.service.arpa. - zone "default.services.arpa." { + zone "default.service.arpa." { type master; file "/etc/bind/master/service.db"; - allow-update { key demo.default.services.arpa.; }; + allow-update { key demo.default.service.arpa.; }; }; Zone Configuration in named.conf $ORIGIN . $TTL 57600 ; 16 hours -default.services.arpa IN SOA ns3.default.services.arpa. postmaster.default.services.arpa. ( +default.service.arpa IN SOA ns3.default.service.arpa. postmaster.default.service.arpa. ( 2951053287 ; serial 3600 ; refresh (1 hour) 1800 ; retry (30 minutes) 604800 ; expire (1 week) 3600 ; minimum (1 hour) ) - NS ns3.default.services.arpa. - SRV 0 0 53 ns3.default.services.arpa. -$ORIGIN default.services.arpa. + NS ns3.default.service.arpa. + SRV 0 0 53 ns3.default.service.arpa. +$ORIGIN default.service.arpa. $TTL 3600 ; 1 hour _ipps._tcp PTR demo._ipps._tcp -$ORIGIN _ipps._tcp.default.services.arpa. +$ORIGIN _ipps._tcp.default.service.arpa. demo TXT "0" - SRV 0 0 9992 demo.default.services.arpa. -$ORIGIN _udp.default.services.arpa. + SRV 0 0 9992 demo.default.service.arpa. +$ORIGIN _udp.default.service.arpa. $TTL 3600 ; 1 hour -_dns-update PTR ns3.default.services.arpa. -$ORIGIN _tcp.default.services.arpa. -_dnssd-srp PTR ns3.default.services.arpa. -$ORIGIN default.services.arpa. +_dns-update PTR ns3.default.service.arpa. +$ORIGIN _tcp.default.service.arpa. +_dnssd-srp PTR ns3.default.service.arpa. +$ORIGIN default.service.arpa. $TTL 300 ; 5 minutes ns3 AAAA 2001:db8:0:1::1 $TTL 3600 ; 1 hour demo AAAA 2001:db8:0:2::1 KEY 513 3 13 ( qweEmaaq0FAWok5//ftuQtZgiZoiFSUsm0srWREdywQU 9dpvtOhrdKWUuPT3uEFF5TZU6B4q1z1I662GdaUwqg== ); alg = ECDSAP256SHA256 ; key id = 15008 AAAA ::1