The ipn.arpa Zone and IPN DNS Operations

Status of This Memo

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Table of Contents

1. Introduction

TODO Introduction¶

2. Conventions and Definitions

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.¶

TODO¶

3. Concept of Operations

The Forwarding Information Base (FIB) of a BP Agent may be populated from a variety of sources. Typically, explicit (manual) configuration is given to associate BP destination endpoints with the Convergence Layer parameters required to establish communication with a responsible receiving BP Agent.¶

A BP Agent may also dynamically create a FIB entry by querying for DNS Resource Records as follows.¶

Consider a space agency with a registered IPN Allocator ID of 978879 that published the following two DNS zones:¶

; zone 978879.ipn.arpa.
@   IN SOA ns1.space-agency.example ...
1   IN PTR lunar-orbiter1.space-agency.example.
2   IN PTR mars-orbiter2.space-agency.example.
500 IN PTR research-department.space-agency.example.


; zone space-agency.example.
@ IN SOA ns1.space-agency.example ...

antenna-relay IN A 192.0.2.1
antenna-relay IN AAAA 2001:db8::1

lunar-orbiter1 IN TXT "{'norad-id': '81111'}}"
_dtn-bundle._tcp.2 IN SRV 1 1 4556 antenna-relay.space-agency.example.

mars-orbiter2 IN TXT "{'norad-id': '82222'}}"
_dtn-bundle._udp.2 IN SRV 1 1 4556 antenna-relay.space-agency.example.

cloud-service IN A 192.0.2.5
cloud-service IN AAAA 2001:db8::5

_dtn-bundle._tcp.research-department IN SRV 1 1 4556 cloud-service.space-agency.example.
_dtn-bundle._udp.research-department IN SRV 1 1 4556 cloud-service.space-agency.example.

A BP Agent, perhaps collocated at a landing station, which had received a Bundle destined for ipn:978879.500.345 could determine the proper TCP and UDP CL IP addresses and ports by:¶

• querying for a PTR record associated with 500.978879.ipn.arpa¶

• (receiving research-department.space-agency.example)¶

• querying for an SRV record associated with _dtn-bundle._tcp.research-department.space-agency.example (ditto for ._udp)¶

• (receiving port 4556 and hostname cloud-service.space-agency.example.)¶

• querying for A and AAAA records for cloud-service.space-agency.example.¶

• (receiving 192.0.2.5 and 2001:db8::5)¶

The BP Agent at the landing station could then attempt to initiated a [TCPCL] or [UDPCL] connection to [2001:db8::5]:4556, for example, and attempt to deliver the given Bundle.¶

Similarly, a researcher attempting to send a Bundle payload to mars-orbiter2.space-agency.example could use a BP Agent capable of querying DNS and learning about the [UDPCL] endpoint at 192.0.2.1:4556. Once the Bundle had been forwarded to antenna-relay.space-agency.example, it would be the antenna-relay's responsibility to forward it to the spacecraft.¶

Any future CLs that define DNS records (e.g. SVCB records, etc) may be added to the space-agency.example zone and, through the use of PTR records in the 978879.ipn.arpa zone, be discovered by appropriately capable BP agents.¶

4. Operational Considerations

TODO Operational¶

Note that use of DNS may not be appropriate for all network environments. Any deployments where querying DNS might not align with reliability or performance requirements are recommended to obtain BP FIB information by other mechanisms (out of scope of this document).¶

5. Security Considerations

TODO Security¶

6. IAB Considerations

The IAB is requested to approve the zone "ipn.arpa" as parent for IPN addresses, similar to in-addr.arpa and ip6.arpa "reverse DNS" for IPv4 and IPv6 addresses (respectively).¶

Per [RFC9758], IPN addresses have an Allocator identifier and an allocator-specific identifier (both 32-bit unsigned integers).¶

7. IANA Considerations

8. References

Acknowledgments

TODO acknowledge.¶

Author's Address