The Dynamic Host Configuration Protocol for IPv6 (DHCPv6) Client Fully Qualified Domain Name (FQDN) Option

Abstract

Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Privacy Considerations for DHCPv6

“…The Client Fully Qualified Domain Name (FQDN) option [RFC4704] is used by DHCPv6 clients and servers to exchange information about the client's FQDN and about who has the responsibility for updating the DNS with the associated AAAA and PTR RRs.…”

“…Client implementations may mistakenly renew temporary addresses if they are not careful (i.e., by including the IA_TA with the same IAID in Renew or Rebind requests, rather than a new IAID --see Section 22.5 of [RFC3315]), thus forfeiting short liveness. [RFC4704] does not explicitly prohibit servers from updating DNS for assigned temporary addresses, and there are implementations that can be configured to do that. However, this is not advised as publishing a client's IPv6 address in DNS that is publicly available is a major privacy breach.…”

“…The Client FQDN option [RFC4704] used along with DNS UPDATE [RFC2136] defines a mechanism that allows both clients and the server to insert information about clients into the DNS domain. Both forward (AAAA) and reverse (PTR) resource records can be updated.…”

IPv6 Site Renumbering Gap Analysis

“…Normal hosts are not suitable to do the update, mainly because of the complex key-management issues inherited from secure DNS mechanisms, so current practices usually assign DHCP servers to act as DNS clients to request that the DNS server update relevant records [RFC4704]. The key-management problem is tractable in the case of updates for a limited number of servers, so Dynamic DNS To address the larger use case of arbitrary non-server hosts being renumbered, DHCP servers have to learn that the relevant hosts have changed their addresses and thus trigger the DDNS update.…”

Resolution of Fully Qualified Domain Name (FQDN) Conflicts among Dynamic Host Configuration Protocol (DHCP) Clients

“…Introduction "The Client FQDN Option" [8] includes a description of the operation of [4] clients and servers that use the DHCPv4 client FQDN option. "The DHCPv6 Client FQDN Option" [9] includes a description of the operation of [5] clients and servers that use the DHCPv6 client FQDN option. Through the use of the client FQDN option, DHCP clients and servers can negotiate the client's FQDN and the allocation of responsibility for updating the DHCP client's A and/or AAAA RRs.…”