SV_RFC1034_5_3_2_Cache_vs_auth - Cache data vs. authoritative data
Verify that a NUT uses the authoritative data in preference to cached data
- If the resolver has direct access to a name server's zones,
it should check to see if the desired data is present in authoritative form,
and if so, use the authoritative data in preference to cached data.
Caching Server
SV_RFC1034_5_3_2_Cache_vs_auth.seq [-tooloption ...]: KOI tool option
See also DNSConfig.pm
This test sequence is following.
Client1 (TN) DNS Server1 (NUT) DNS Server2 (TN) DNS Server3 (TN) DNS Server4 (TN)
| | | | |
|----------------------------->| | | |
| 1. Send standard query | | | |
| QNAME=A.example.org | | | |
| QTYPE=A | | | |
| | | | |
| |-------------------------------->| | |
| | 2. Send standard query | | |
| | QNAME=A.example.org | | |
| | QTYPE=A | | |
| | | | |
| |<--------------------------------| | |
| | 3. Send standard response | | |
| | QNAME=A.example.org | | |
| | QTYPE=A | | |
| | AUTHORITY Name=org | | |
| | AUTHORITY Name Server | | |
| | =NS3.example.org | | |
| | ADDITIONAL Name=NS3.example.org| | |
| | ADDITIONAL Address=192.168.1.30| | |
| | | | |
| |------------------------------------------------------------------->| |
| | | 4. Send standard query | |
| | | QNAME=A.example.org | |
| | | QTYPE=A | |
| | | | |
| |<-------------------------------------------------------------------| |
| | | 5. Send standard response | |
| | | QNAME=A.example.org | |
| | | QTYPE=A | |
| | | AUTHORITY Name=example.org | |
| | | AUTHORITY Name Server | |
| | | =NS4.example.org | |
| | | ADDITIONAL Name=NS4.example.org | |
| | | ADDITIONAL Address=192.168.1.40 | |
| | | | |
| |------------------------------------------------------------------------------------------------------>|
| | | | 6. Send standard query |
| | | | QNAME=A.example.org |
| | | | QTYPE=A |
| | | | |
| |<------------------------------------------------------------------------------------------------------|
| | | | 7. Send standard response |
| | | | QNAME=A.example.org |
| | | | QTYPE=A |
| | | | ANSWER Name=A.example.org |
| | | | ANSWER Address=192.168.1.10 |
| | | | AUTHORITY Name=example.org |
| | | | AUTHORITY Name Server |
| | | | =NS4.example.org |
| | | | ADDITIONAL Name=NS4.example.org |
| | | | ADDITIONAL Address=192.168.1.40 |
|<-----------------------------| | | |
| 8. Standard query response | | | |
| QNAME=A.example.org | | | |
| QTYPE=A | | | |
| ANSWER Name=A.example.org | | | |
| ANSWER Address=192.168.1.10 | | | |
| AUTHORITY Name=example.org | | | |
| AUTHORITY Name Server | | | |
| =NS4.example.org | | | |
| | | | |
|----------------------------->| | | |
| 9. Send standard query | | | |
| QNAME=A.example.org | | | |
| QTYPE=A | | | |
| | *disregard the cached data | | |
| |-------------------------------->| | |
| | 10. Send standard query | | |
| | QNAME=A.example.org | | |
| | QTYPE=A | | |
| | | | |
| |<--------------------------------| | |
| | 11. Send standard response | | |
| | QNAME=A.example.org | | |
| | QTYPE=A | | |
| | AUTHORITY Name=org | | |
| | AUTHORITY Name Server | | |
| | =NS3.example.org | | |
| | ADDITIONAL Name=NS3.example.org| | |
| | ADDITIONAL Address=192.168.1.30| | |
| | | | |
| |------------------------------------------------------------------->| |
| | | 12. Send standard query | |
| | | QNAME=A.example.org | |
| | | QTYPE=A | |
| | | | |
| |<-------------------------------------------------------------------| |
| | | 13. Send standard response | |
| | | QNAME=A.example.org | |
| | | QTYPE=A | |
| | | AUTHORITY Name=example.org | |
| | | AUTHORITY Name Server | |
| | | =NS4.example.org | |
| | | ADDITIONAL Name=NS4.example.org | |
| | | ADDITIONAL Address=192.168.1.40 | |
| | | | |
| |------------------------------------------------------------------------------------------------------>|
| | | | 14. Send standard query |
| | | | QNAME=A.example.org |
| | | | QTYPE=A |
| | | | |
| |<------------------------------------------------------------------------------------------------------|
| | | | 15. Send standard response |
| | | | QNAME=A.example.org |
| | | | QTYPE=A |
| | | | ANSWER Name=A.example.org |
| | | | ANSWER Address=192.168.1.10 |
| | | | AUTHORITY Name=example.org |
| | | | AUTHORITY Name Server |
| | | | =NS4.example.org |
| | | | ADDITIONAL Name=NS4.example.org |
| | | | ADDITIONAL Address=192.168.1.40 |
|<-----------------------------| | | |
| 16. Standard query response | | | |
| QNAME=A.example.org | | | |
| QTYPE=A | | | |
| ANSWER Name=A.example.org | | | |
| ANSWER Address=192.168.1.10 | | | |
| AUTHORITY Name=example.org | | | |
| AUTHORITY Name Server | | | |
| =NS4.example.org | | | |
v v v v v
1. TN send standard query QNAME=A.example.org, QTYPE=A to NUT.
2. NUT transmits standard query to DNS Server2 (TN: root name server) (Judgment *2)
3. TN send query response to NUT w/ AUTHORITY Name=org, AUTHORITY Name Server=NS3.example.org.
4. NUT transmits standard query QNAME=A.example.org, QTYPE=A to DNS Server3 (TN: NS3.example.org) (Judgment *4)
5. TN send query response to NUT w/ AUTHORITY Name=example.org, AUTHORITY Name Server=NS4.example.org.
6. NUT transmits standard query QNAME=A.example.org, QTYPE=A to DNS Server4 (TN: NS4.example.org) (Judgment *6)
7. TN send query response to ANSWER Name=A.example.org, ANSWER Address=192.168.1.10 to NUT.
8. NUT transmits query response to DNS Client1 (TN) (Judgment *8)
9. TN send standard query QNAME=A.example.org, QTYPE=A to NUT.
10. NUT transmits standard query to DNS Server2 (TN: root name server) (Judgment *10)
11. TN send query response to NUT w/ AUTHORITY Name=org, AUTHORITY Name Server=NS3.example.org.
12. NUT transmits standard query QNAME=A.example.org, QTYPE=A to DNS Server3 (TN: NS3.example.org) (Judgment *12)
13. TN send query response to NUT w/ AUTHORITY Name=example.org, AUTHORITY Name Server=NS4.example.org.
14. NUT transmits standard query QNAME=A.example.org, QTYPE=A to DNS Server4 (TN: NS4.example.org) (Judgment *14)
15. TN send query response to ANSWER Name=A.example.org, ANSWER Address=192.168.1.10 to NUT.
16. NUT transmits query response to DNS Client1 (TN) (Judgment *16)
- Packet Description
- 1st packet.
Standard query from DNS Client1 (TN) to Server1 (NUT)
|
IP Header |
Source Address |
CL1_NETZ |
Destination Address |
NUT_NETZ |
UDP Header |
Src Port |
2000 |
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 |
A.example.org |
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
- 2nd packet.
Standard query from DNS Server1 (NUT) to Server2 (TN)
|
IP Header |
Source Address |
NUT_NETZ |
Destination Address |
SV2_NETY |
UDP Header |
Src Port |
any |
Dst Port |
53 |
DNS Header |
ID |
any |
QR |
0 |
OPCODE |
0 |
AA |
any |
TC |
0 |
RD |
0 |
RA |
any |
Z |
any |
RCODE |
any |
QDCOUNT |
1 |
ANCOUNT |
0 |
NSCOUNT |
0 |
ARCOUNT |
any |
DNS Question section |
QNAME |
A.example.org |
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
- 3rd packet.
Standard query response from DNS Server2 (TN) to Server1 (NUT)
|
IP Header |
Source Address |
SV2_NETY |
Destination Address |
NUT_NETZ |
UDP Header |
Src Port |
53 |
Dst Port |
Value that NUT uses |
DNS Header |
ID |
Value that NUT uses |
QR |
1 |
OPCODE |
0 |
AA |
0 |
TC |
0 |
RD |
0 |
RA |
0 |
Z |
0 |
RCODE |
0 |
QDCOUNT |
1 |
ANCOUNT |
0 |
NSCOUNT |
1 |
ARCOUNT |
1 |
DNS Question section |
QNAME |
A.example.org
|
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
DNS Authority section |
NAME |
org (Pointer 0xC016) |
TYPE |
NS (0x0002) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
6 |
NSDNAME |
NS3.example.org (NS3 + Pointer 0xC00E) |
DNS Additional section |
NAME |
NS3.example.org (Pointer 0xC02B) |
TYPE
|
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.30 |
- 4th packet.
Standard query from DNS Server1 (NUT) to Server3 (TN)
|
IP Header |
Source Address |
NUT_NETZ |
Destination Address |
SV3_NETY |
UDP Header |
Src Port |
any |
Dst Port |
53 |
DNS Header |
ID |
any |
QR |
0 |
OPCODE |
0 |
AA |
any |
TC |
0 |
RD |
0 |
RA |
any |
Z |
any |
RCODE |
any |
QDCOUNT |
1 |
ANCOUNT |
0 |
NSCOUNT |
0 |
ARCOUNT |
any |
DNS Question section |
QNAME |
A.example.org |
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
- 5th packet.
Standard query response from DNS Server3 (TN) to Server1 (NUT)
|
IP Header |
Source Address |
SV3_NETY |
Destination Address |
NUT_NETZ |
UDP Header |
Src Port |
Value that NUT uses |
Dst Port |
53 |
DNS Header |
ID |
Value that NUT uses |
QR |
1 |
OPCODE |
0 |
AA |
0 |
TC |
0 |
RD |
0 |
RA |
0 |
Z |
0 |
RCODE |
0 |
QDCOUNT |
1 |
ANCOUNT |
0 |
NSCOUNT |
1 |
ARCOUNT |
1 |
DNS Question section |
QNAME |
A.example.org
|
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
DNS Authority section |
NAME |
example.org (Pointer 0xC00E) |
TYPE |
NS (0x0002) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
6 |
NSDNAME |
NS4.example.org (NS4 + Pointer 0xC00E) |
DNS Additional section |
NAME |
NS4.example.org (Pointer 0xC02B) |
TYPE
|
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.40 |
- 6th packet.
Standard query from DNS Server1 (NUT) to Server4 (TN)
|
IP Header |
Source Address |
NUT_NETZ |
Destination Address |
SV4_NETY |
UDP Header |
Src Port |
any |
Dst Port |
53 |
DNS Header |
ID |
any |
QR |
0 |
OPCODE |
0 |
AA |
any |
TC |
0 |
RD |
0 |
RA |
any |
Z |
any |
RCODE |
any |
QDCOUNT |
1 |
ANCOUNT |
0 |
NSCOUNT |
0 |
ARCOUNT |
any |
DNS Question section |
QNAME |
A.example.org |
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
- 7th packet.
Standard query response from DNS Server4 (TN) to Server1 (NUT)
|
IP Header |
Source Address |
SV4_NETY |
Destination Address |
NUT_NETZ |
UDP Header |
Src Port |
Value that NUT uses |
Dst Port |
53 |
DNS Header |
ID |
Value that NUT uses |
QR |
1 |
OPCODE |
0 |
AA |
1 |
TC |
0 |
RD |
0 |
RA |
0 |
Z |
0 |
RCODE |
0 |
QDCOUNT |
1 |
ANCOUNT |
1 |
NSCOUNT |
1 |
ARCOUNT |
1 |
DNS Question section |
QNAME |
A.example.org
|
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
DNS Answer section |
NAME |
A.example.org (Pointer 0xC00C)
|
TYPE |
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.10 |
DNS Authority section |
NAME |
example.org (Pointer 0xC00E) |
TYPE |
NS (0x0002) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
6 |
NSDNAME |
NS4.example.org (NS4 + Pointer 0xC00E) |
DNS Additional section |
NAME |
NS4.example.org (Pointer 0xC03B) |
TYPE
|
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.40 |
- 8th packet.
Standard query response from DNS Server1 (NUT) to Client1 (TN)
|
IP Header |
Source Address |
NUT_NETZ |
Destination Address |
CL1_NETZ |
UDP Header |
Src Port |
53 |
Dst Port |
2000 |
DNS Header |
ID |
0x1000 |
QR |
1 |
OPCODE |
0 |
AA |
0 |
TC |
0 |
RD |
1 |
RA |
1 |
Z |
0 |
RCODE |
0 |
QDCOUNT |
1 |
ANCOUNT |
1 |
NSCOUNT |
1 |
ARCOUNT |
1 |
DNS Question section |
QNAME |
A.example.org |
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
DNS Answer section |
NAME |
A.example.org (Pointer 0xC00C)
|
TYPE |
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.10 |
DNS Authority section |
NAME |
example.org (Pointer 0xC00E) |
TYPE |
NS (0x0002) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
6 |
NSDNAME |
NS4.example.org (NS4 + Pointer 0xC00E) |
DNS Additional section |
NAME |
NS4.example.org (Pointer 0xC03B) |
TYPE
|
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.40 |
- 9th packet.
Standard query from DNS Client1 (TN) to Server1 (NUT)
|
IP Header |
Source Address |
CL1_NETZ |
Destination Address |
NUT_NETZ |
UDP Header |
Src Port |
2000 |
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 |
A.example.org |
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
- 10th packet.
Standard query from DNS Server1 (NUT) to Server2 (TN)
|
IP Header |
Source Address |
NUT_NETZ |
Destination Address |
SV2_NETY |
UDP Header |
Src Port |
any |
Dst Port |
53 |
DNS Header |
ID |
any |
QR |
0 |
OPCODE |
0 |
AA |
any |
TC |
0 |
RD |
0 |
RA |
any |
Z |
any |
RCODE |
any |
QDCOUNT |
1 |
ANCOUNT |
0 |
NSCOUNT |
0 |
ARCOUNT |
any |
DNS Question section |
QNAME |
A.example.org |
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
- 11th packet.
Standard query response from DNS Server2 (TN) to Server1 (NUT)
|
IP Header |
Source Address |
SV2_NETY |
Destination Address |
NUT_NETZ |
UDP Header |
Src Port |
53 |
Dst Port |
Value that NUT uses |
DNS Header |
ID |
Value that NUT uses |
QR |
1 |
OPCODE |
0 |
AA |
0 |
TC |
0 |
RD |
0 |
RA |
0 |
Z |
0 |
RCODE |
0 |
QDCOUNT |
1 |
ANCOUNT |
0 |
NSCOUNT |
1 |
ARCOUNT |
1 |
DNS Question section |
QNAME |
A.example.org
|
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
DNS Authority section |
NAME |
org (Pointer 0xC016) |
TYPE |
NS (0x0002) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
6 |
NSDNAME |
NS3.example.org (NS3 + Pointer 0xC00E) |
DNS Additional section |
NAME |
NS3.example.org (Pointer 0xC02B) |
TYPE
|
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.30 |
- 12th packet.
Standard query from DNS Server1 (NUT) to Server3 (TN)
|
IP Header |
Source Address |
NUT_NETZ |
Destination Address |
SV3_NETY |
UDP Header |
Src Port |
any |
Dst Port |
53 |
DNS Header |
ID |
any |
QR |
0 |
OPCODE |
0 |
AA |
any |
TC |
0 |
RD |
0 |
RA |
any |
Z |
any |
RCODE |
any |
QDCOUNT |
1 |
ANCOUNT |
0 |
NSCOUNT |
0 |
ARCOUNT |
any |
DNS Question section |
QNAME |
A.example.org |
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
- 13th packet.
Standard query response from DNS Server3 (TN) to Server1 (NUT)
|
IP Header |
Source Address |
SV3_NETY |
Destination Address |
NUT_NETZ |
UDP Header |
Src Port |
Value that NUT uses |
Dst Port |
53 |
DNS Header |
ID |
Value that NUT uses |
QR |
1 |
OPCODE |
0 |
AA |
0 |
TC |
0 |
RD |
0 |
RA |
0 |
Z |
0 |
RCODE |
0 |
QDCOUNT |
1 |
ANCOUNT |
1 |
NSCOUNT |
1 |
ARCOUNT |
1 |
DNS Question section |
QNAME |
A.example.org
|
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
DNS Authority section |
NAME |
example.org (Pointer 0xC00E) |
TYPE |
NS (0x0002) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
6 |
NSDNAME |
NS4.example.org (NS4 + Pointer 0xC00E) |
DNS Additional section |
NAME |
NS4.example.org (Pointer 0xC02B) |
TYPE
|
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.40 |
- 14th packet.
Standard query from DNS Server1 (NUT) to Server4 (TN)
|
IP Header |
Source Address |
NUT_NETZ |
Destination Address |
SV4_NETY |
UDP Header |
Src Port |
any |
Dst Port |
53 |
DNS Header |
ID |
any |
QR |
0 |
OPCODE |
0 |
AA |
any |
TC |
0 |
RD |
0 |
RA |
any |
Z |
any |
RCODE |
any |
QDCOUNT |
1 |
ANCOUNT |
0 |
NSCOUNT |
0 |
ARCOUNT |
any |
DNS Question section |
QNAME |
A.example.org |
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
- 15th packet.
Standard query response from DNS Server4 (TN) to Server1 (NUT)
|
IP Header |
Source Address |
SV4_NETY |
Destination Address |
NUT_NETZ |
UDP Header |
Src Port |
Value that NUT uses |
Dst Port |
53 |
DNS Header |
ID |
Value that NUT uses |
QR |
1 |
OPCODE |
0 |
AA |
1 |
TC |
0 |
RD |
0 |
RA |
1 |
Z |
0 |
RCODE |
0 |
QDCOUNT |
1 |
ANCOUNT |
1 |
NSCOUNT |
1 |
ARCOUNT |
1 |
DNS Question section |
QNAME |
A.example.org
|
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
DNS Answer section |
NAME |
A.example.org (Pointer 0xC00C)
|
TYPE |
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.10 |
DNS Authority section |
NAME |
example.org (Pointer 0xC00E) |
TYPE |
NS (0x0002) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
6 |
NSDNAME |
NS4.example.org (NS4 + Pointer 0xC00E) |
DNS Additional section |
NAME |
NS4.example.org (Pointer 0xC03B) |
TYPE
|
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.40 |
- 16th packet.
Standard query response from DNS Server1 (NUT) to Client1 (TN)
|
IP Header |
Source Address |
NUT_NETZ |
Destination Address |
CL1_NETZ |
UDP Header |
Src Port |
53 |
Dst Port |
2000 |
DNS Header |
ID |
0x1000 |
QR |
1 |
OPCODE |
0 |
AA |
0 |
TC |
0 |
RD |
1 |
RA |
1 |
Z |
0 |
RCODE |
0 |
QDCOUNT |
1 |
ANCOUNT |
1 |
NSCOUNT |
1 |
ARCOUNT |
1 |
DNS Question section |
QNAME |
A.example.org |
QTYPE |
A (0x0001) |
QCLASS |
IN (0x0001) |
DNS Answer section |
NAME |
A.example.org (Pointer 0xC00C)
|
TYPE |
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.10 |
DNS Authority section |
NAME |
example.org (Pointer 0xC00E) |
TYPE |
NS (0x0002) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
6 |
NSDNAME |
NS4.example.org (NS4 + Pointer 0xC00E) |
DNS Additional section |
NAME |
NS4.example.org (Pointer 0xC03B) |
TYPE
|
A (0x0001) |
CLASS |
IN (0x0001) |
TTL |
1 day (86400) |
RDLENGTH |
4 |
ADDRESS |
192.168.1.40 |
- Exp.
NUT_NETZ |
DNS Server1's (NUT) Net-z address |
CL1_NETZ |
DNS Client1's (TN) Net-z address |
SV2_NETY |
DNS Server2's (TN) Net-y address |
SV3_NETY |
DNS Server3's (TN) Net-y address |
SV4_NETY |
DNS Server4's (TN) Net-y address |
2. Received standard query including QNAME=A.example.org, QTYPE=A.
4. Received standard query including QNAME=A.example.org, QTYPE=A.
6. Received standard query including QNAME=A.example.org, QTYPE=A.
8. Received standard query response including correct address in the ADDRESS field.
10. Received standard query including QNAME=A.example.org, QTYPE=A.
12. Received standard query including QNAME=A.example.org, QTYPE=A.
14. Received standard query including QNAME=A.example.org, QTYPE=A.
16. Received standard query response including correct address in the ADDRESS field.
None
RFC1034 DOMAIN NAMES - CONCEPTS AND FACILITIES
5.3.2. Resouces
5.3.3. Algorithm
RFC1035 DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION
7.4. Using the cache