NAME

        SV_RFC1035_6_2_omit_additional - Duplicate answer is omitted from the additional section

VERIFICATION POINTS

        Verify that a NUT omits duplicate answer from the additional section

When composing a response, RRs which are to be inserted in the additional section, but duplicate RRs in the answer or authority sections, may be omitted from the additional section.

A Resource Record Set should only be included once in any DNS reply. It may occur in any of the Answer, Authority, or Additional Information sections, as required. However it should not be repeated in the same, or any other, section, except where explicitly required by a specification.

TARGET

        Authoritative Server

SYNOPSIS

	SV_RFC1035_6_2_omit_additional.seq [-tooloption ...]: KOI tool option
	See also DNSConfig.pm

INITIALIZATION

Network Topology

        AP Server1 (TN)
          |3ffe:501:ffff:101::10
          |192.168.1.10
          |
Net-y   --+--------+-------------------------- 3ffe:501:ffff:101::/64 
                   |                           192.168.1/24
                   |
                   |
                 Router (TN)
                   |3ffe:501:ffff:100::1
                   |192.168.0.1
                   |
                   |
Net-z   --+--------+-----------------+-------- 3ffe:501:ffff:100::/64 
          |                          |          192.168.0/24
          |                          |
        DNS Server1 (NUT)            DNS Client1 (TN)
           3ffe:501:ffff:100::XXXX     3ffe:501:ffff:100::20 
           192.168.0.10                192.168.0.20
	

	XXXX: EUI64

Setup

Set the DNS Server1's (NUT) address as above mentioned Network Topology.

Configure the Server1's (NUT) zone file to response query from TN.

Example of example.com zone file:

$TTL    86400           ; TTL of 1 day
@ IN SOA NS1.example.com. root.example.com. (
	2005081600	; serial
	3600		; refresh every 1 hr
	900		; retry every 15 min
	604800		; expire after a week
	3600		; Minimum TTL of a 1 hr
)
;
	IN	NS	NS1.example.com.
NS1	IN	A	192.168.0.10
;
A	IN	A	192.168.1.10

TEST PROCEDURE

        This test sequence is following.

    DNS Client1 (TN)                       DNS Server1 (NUT)
        |                                      |
        |------------------------------------->|
        |   1. Send standard query             |
        |       QNAME=NS1.example.com          |
        |       QTYPE=A                        |
        |                                      |
        |<-------------------------------------|
        |   2. Standard query response         |
              ANSWER Name=NS1.example.com      |
        |     ANSWER Address=192.168.0.10      |
        |     AUTHORITY Name=example.com       |
        |     AUTHORITY Nsdname=NS1.example.com|
        |                                      |
        v                                      v

        1. TN send standard query QNAME=NS1.example.com, QTYPE=A, QCLASS=* to NUT.
        2. NUT reply query response w/ A=192.168.0.10 to TN (Judgment *2)

Packet Description

1st packet.

Standard query from DNS Client1 (TN) to Server1 (NUT)
IP Header	Source Address	CL1_NETZ
IP Header	Destination Address	NUT_NETZ
UDP Header	Src Port	2000
UDP Header	Dst Port	53
DNS Header	ID	0x1000
	QR	0
	OPCODE	0
	AA	0
	TC	0
	RD	1
	RA	0
	Z	0
	RCODE	0
	QDCOUNT	1
	ANCOUNT	0
	NSCOUNT	0
	ARCOUNT	0
DNS Question section	QNAME	NS1.example.com
	QTYPE	A (0x0001)
	QCLASS	IN (0x0001)

2nd packet.

Standard query response from DNS Server1 (NUT) to Client1 (TN)
IP Header	Source Address	NUT_NETZ
IP Header	Destination Address	CL1_NETZ
UDP Header	Src Port	53
UDP Header	Dst Port	2000
DNS Header	ID	0x1000
	QR	1
	OPCODE	0
	AA	1
	TC	0
	RD	1
	RA	ANY
	Z	0
	RCODE	0
	QDCOUNT	1
	ANCOUNT	1
	NSCOUNT	1
	ARCOUNT	1
DNS Question section	QNAME	NS1.example.com
	QTYPE	A (0x0001)
	QCLASS	IN (0x0001)
DNS Answer section	NAME	NS1.example.com (Pointer 0xC00C)
	TYPE	A (0x0001)
	CLASS	IN (0x0001)
	TTL	1 day (86400)
	RDLENGTH	4
	ADDRESS	192.168.0.10
DNS Authority section	NAME	example.com (Pointer 0xC010)
	TYPE	NS (0x0002)
	CLASS	IN (0x0001)
	TTL	1 day (86400)
	RDLENGTH	2
	NSDNAME	NS1.example.com (Pointer 0xC00C)

Exp.

NUT_NETZ	DNS Server1's (NUT) Net-z address
NUT_NETZ2	DNS Server1's (NUT) another Net-z address
CL1_NETZ	DNS Client1's (TN) Net-z address

JUDGMENT

        2. Received standard query response that must not include Additional section.

TERMINATION

        None

REFERENCE

        RFC1035 DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION
        6.2. Standard query processing

        RFC2181 Clarifications to the DNS Specification
        5.5. Sending RRSets (reprise)