NAME

        SV_RFC1034_5_2_2_mutiple_aliases - Multiple levels of aliases should be avoided, but should not be signaled as an error

VERIFICATION POINTS

        Verify that a NUT does not signal as an error when defined multiple levels of aliases.

Several special conditions can occur with aliases. Multiple levels of

aliases should be avoided due to their lack of efficiency, but should

not be signalled as an error.

TARGET

        Authoritative Server

SYNOPSIS

	SV_RFC1034_5_2_2_mutiple_aliases.seq [-tooloption ...]: KOI tool option
	See also DNSConfig.pm

INITIALIZATION

Network Topology

        AP Server1 (TN)
          |3ffe:501:ffff:101::10,11
          |192.168.1.10.11
          |
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	192.168.0.10
;
B	IN	CNAME	C.example.com.
C	IN	CNAME	A.example.com.

TEST PROCEDURE

        This test sequence is following.

    DNS Client1 (TN)                       DNS Server1 (NUT)
        |                                      |
        |------------------------------------->|
        |   1. Send standard query             |
        |       QNAME=B.example.com            |
        |       QTYPE=CNAME                    |
        |                                      |
        |<-------------------------------------|
        |   2. Standard query response         |
        |       QNAME=B.example.com            |
        |       QTYPE=CNAME                    |
        |       ANSWER Name=B.example.com      |
        |       ANSWER Type=CNAME              |
        |       ANSWER CNAME=C.example.com     |
        | *at lease include this Answer section|
        |------------------------------------->|
        |   3. Send standard query             |
        |       QNAME=C.example.com            |
        |       QTYPE=CNAME                    |
        |                                      |
        |<-------------------------------------|
        |   4. Standard query response         |
        |       QNAME=C.example.com            |
        |       QTYPE=CNAME                    |
        |       ANSWER Name=C.example.com      |
        |       ANSWER Type=CNAME              |
        |       ANSWER CNAME=A.example.com     |
        |                                      |
        |                                      |
        v                                      v

        1. TN send standard query QNAME=B.example.com, QTYPE=A to NUT.
        2. NUT reply query response including CNAME=C.example.com to TN (Judgment *2)
        3. TN send standard query QNAME=C.example.com, QTYPE=A to NUT.
        4. NUT reply query response including CNAME=A.example.com to TN (Judgment *4)

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	B.example.com
	QTYPE	CNAME (0x0005)
	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	ANY
	TC	0
	RD	1
	RA	ANY
	Z	0
	RCODE	0
	QDCOUNT	1
	ANCOUNT	1
	NSCOUNT	1
	ARCOUNT	1
DNS Question section	QNAME	B.example.com
	QTYPE	CNAME (0x0005)
	QCLASS	IN (0x0001)
DNS Answer section	NAME	B.example.com (Pointer 0xC00C)
	TYPE	CNAME (0x0005)
	CLASS	IN (0x0001)
	TTL	1 day (86400)
	RDLENGTH	4
	CNAME	C.example.com (C + Pointer 0xC00E)
DNS Authority section	NAME	example.com (Pointer 0xC00E)
	TYPE	NS (0x0002)
	CLASS	IN (0x0001)
	TTL	1 day (86400)
	RDLENGTH	6
	NSDNAME	NS1.example.com (NS1 + Pointer 0xC00E)
DNS Additional section	NAME	NS1.example.com (Pointer 0xC03B)
	TYPE	A (0x0001)
	CLASS	IN (0x0001)
	TTL	1 day (86400)
	RDLENGTH	4
	ADDRESS	192.168.0.10

3rd 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	0x1001
	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	C.example.com
	QTYPE	CNAME (0x0005)
	QCLASS	IN (0x0001)

4th 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	0x1001
	QR	1
	OPCODE	0
	AA	ANY
	TC	0
	RD	1
	RA	ANY
	Z	0
	RCODE	0
	QDCOUNT	1
	ANCOUNT	1
	NSCOUNT	1
	ARCOUNT	1
DNS Question section	QNAME	C.example.com
	QTYPE	CNAME (0x0005)
	QCLASS	IN (0x0001)
DNS Answer section	NAME	C.example.com (Pointer 0xC00C)
	TYPE	CNAME (0x0005)
	CLASS	IN (0x0001)
	TTL	1 day (86400)
	RDLENGTH	4
	CNAME	A.example.com (A + Pointer 0xC00E)
DNS Authority section	NAME	example.com (Pointer 0xC00E)
	TYPE	NS (0x0002)
	CLASS	IN (0x0001)
	TTL	1 day (86400)
	RDLENGTH	6
	NSDNAME	NS1.example.com (NS1 + Pointer 0xC00E)
DNS Additional section	NAME	NS1.example.com (Pointer 0xC03B)
	TYPE	A (0x0001)
	CLASS	IN (0x0001)
	TTL	1 day (86400)
	RDLENGTH	4
	ADDRESS	192.168.0.10

Exp.

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

JUDGMENT

        2. Received standard query response including CNAME for B.example.com.
        4. Received standard query response including CNAME for C.example.com.

TERMINATION

        None

REFERENCE

        RFC1034 DOMAIN NAMES - CONCEPTS AND FACILITIES
        5.2.2. Aliases