

Supported Resource Records

Resource Records supported in DMS backend.  More can easily be added.

Reference information from http://en.wikipedia.org/wiki/List_of_DNS_record_types
CLASSES
    builtins.object
        ResourceRecord
            RR_A
            RR_AAAA
            RR_CERT		Certificate record 	Stores PKIX, SPKI, PGP, etc.
            RR_CNAME
            RR_DS               Delegation signer 	The record used to identify the
                                                        DNSSEC signing key of a delegated zone
            RR_HINFO
            RR_IPSECKEY         IPSEC Key 	     Key record that can be used with IPSEC
            RR_KX               Key eXchanger record 	Used with some cryptographic systems
                                                        (not including DNSSEC) to identify a
                                                        key management agent for the
                                                        associated domain-name. Note that
                                                        this has nothing to do with DNS
                                                        Security. It is Informational status,
                                                        rather than being on the IETF
                                                        standards-track. It has always had
                                                        limited deployment, but is still in
                                                        use.
            RR_LOC             Location record 	        Specifies a geographical location 
                                                        associated with a domain name
            RR_MX
            RR_NAPTR           Naming Authority Pointer Allows regular expression based
                                                        rewriting of domain names which can
                                                        then be used as URIs, further domain
                                                        names to lookups, etc.
            RR_NS
            RR_NSAP            Access Point address
            RR_PTR
            RR_RP
            RR_SOA
            RR_SPF             Sender Policy Framework 	Specified as part of the SPF protocol
                                                        in preference to the earlier
                                                        provisional practice of storing SPF
                                                        data in TXT records. Uses the same
                                                        format as the earlier TXT record.
            RR_SRV            Service locator 	        Generalized service location record,
                                                        used for newer protocols instead of
                                                        creating protocol-specific records
                                                        such as MX.
            RR_SSHFP          SSH Public Key Fingerprint Resource record for publishing SSH
                                                        public host key fingerprints in the
                                                        DNS System, in order to aid in
                                                        verifying the authenticity of the
                                                        host.
            RR_TXT

From RFC 2782 
    Here is the format of the SRV RR, whose DNS type code is 33:

        _Service._Proto.Name TTL Class SRV Priority Weight Port Target

        (There is an example near the end of this document.)

   Service
        The symbolic name of the desired service, as defined in Assigned
        Numbers [STD 2] or locally.  An underscore (_) is prepended to
        the service identifier to avoid collisions with DNS labels that
        occur in nature.

        Some widely used services, notably POP, don't have a single
        universal name.  If Assigned Numbers names the service
        indicated, that name is the only name which is legal for SRV
        lookups.  The Service is case insensitive.

   Proto
        The symbolic name of the desired protocol, with an underscore
        (_) prepended to prevent collisions with DNS labels that occur
        in nature.  _TCP and _UDP are at present the most useful values
        for this field, though any name defined by Assigned Numbers or
        locally may be used (as for Service).  The Proto is case
        insensitive.

   Name
        The domain this RR refers to.  The SRV RR is unique in that the
        name one searches for is not this name; the example near the end
        shows this clearly.

   TTL
        Standard DNS meaning [RFC 1035].

   Class
        Standard DNS meaning [RFC 1035].   SRV records occur in the IN
        Class.

   Priority
        The priority of this target host.  A client MUST attempt to
        contact the target host with the lowest-numbered priority it can
        reach; target hosts with the same priority SHOULD be tried in an
        order defined by the weight field.  The range is 0-65535.  This
        is a 16 bit unsigned integer in network byte order.

   Weight
        A server selection mechanism.  The weight field specifies a
        relative weight for entries with the same priority. Larger
        weights SHOULD be given a proportionately higher probability of
        being selected. The range of this number is 0-65535.  This is a
        16 bit unsigned integer in network byte order.  Domain
        administrators SHOULD use Weight 0 when there isn't any server
        selection to do, to make the RR easier to read for humans (less
        noisy).  In the presence of records containing weights greater
        than 0, records with weight 0 should have a very small chance of
        being selected.


From RFC 4034
    
5.4. DS RR Example


   The following example shows a DNSKEY RR and its corresponding DS RR.

   dskey.example.com. 86400 IN DNSKEY 256 3 5 ( AQOeiiR0GOMYkDshWoSKz9Xz
                                             fwJr1AYtsmx3TGkJaNXVbfi/
                                             2pHm822aJ5iI9BMzNXxeYCmZ
                                             DRD99WYwYqUSdjMmmAphXdvx
                                             egXd/M5+X7OrzKBaMbCVdFLU
                                             Uh6DhweJBjEVv5f2wwjM9Xzc
                                             nOf+EPbtG9DMBmADjFDc2w/r
                                             ljwvFw==
                                             ) ;  key id = 60485

   dskey.example.com. 86400 IN DS 60485 5 1 ( 2BB183AF5F22588179A53B0A
                                              98631FAD1A292118 )

   The first four text fields specify the name, TTL, Class, and RR type
   (DS).  Value 60485 is the key tag for the corresponding
   "dskey.example.com." DNSKEY RR, and value 5 denotes the algorithm
   used by this "dskey.example.com." DNSKEY RR.  The value 1 is the
   algorithm used to construct the digest, and the rest of the RDATA
   text is the digest in hexadecimal.

