CL_RFC2308_5_expire_cache_NODATA - TTL expired negative cache MUST NOT be used (NODATA)
Verify that a NUT does not use the TTL expired negative cache.
- This TTL decrements in a similar manner to a normal cached answer and
- upon reaching zero (0) indicates the cached negative answer MUST NOT
- be used again.
Client (with Caching function)
CL_RFC2308_5_expire_cache_NODATA.seq [-tooloption ...]: KOI tool option
See also DNSConfig.pm
AP Server1(TN):A.example.com DNS Server1(TN)
|3ffe:501:ffff:101::10 |3ffe:501:ffff:101::20
|192.168.1.10 |192.168.1.20
| |
Net-y --+--------+-----------------------+-------- 3ffe:501:ffff:101::/64
| 192.168.1/24
|
|
ROUTER1(TN)
|3ffe:501:ffff:100::1
|192.168.0.1
|
Net-z --+--------+-------------------------------- 3ffe:501:ffff:100::/64
| 192.168.0/24
DNS Client1(NUT)
3ffe:501:ffff:100:XXXX
192.168.0.10
XXXX: EUI64 address
Setup
Set the DNS Server1(TN)'s address on NUT as above mentioned Network Topology.
Pre-Sequence
In order to send the query for A type(IN class) of AP Server1(TN):A.example.com to the DNS Server1(TN),
NUT is configured.
This test sequence is following.
DNS Client1 (NUT) DNS Server1 (TN)
| |
|--------------------------------------------->|
| 1. Send standard query |
| QNAME=A.example.com |
| QTYPE=A |
| |
|<---------------------------------------------|
| 2. Standard query response |
| NODATA |
| TTL=15 seconds |
| |
// wait 15 seconds //
| |
|--------------------------------------------->|
| 3. Send standard query |
| QNAME=A.example.com |
| QNAME=A |
| |
v v
1. NUT send standard query to TN.
Judgment (Check *1)
2. TN send standard query response to NUT.
3. NUT send standard query to TN.
Judgment (Check *3)
Packet Description
1st Packet
|
1. Standard query from DNS Client1 (NUT) to DNS Server1 (TN)
|
| IP Header |
Source Address |
NUT_NETZ |
| Destination Address |
SV_NETY |
UDP Header
|
Src Port
|
any
|
Dst Port
|
53
|
DNS Header
|
ID |
any |
QR
|
0
|
OPCODE
|
0
|
AA
|
any
|
| TC |
0 |
| RD |
any |
RA
|
any
|
Z
|
any
|
RCODE
|
any
|
QDCOUNT
|
1
|
ANCOUNT
|
0
|
NSCOUNT
|
0
|
ARCOUNT
|
any
|
DNS Question section
|
QNAME |
A.example.com
|
QTYPE
|
A (0x0001)
|
QCLASS
|
IN (0x0001)
|
2nd packet.
|
2. Standard query response from DNS Server1 (TN) to Client1 (NUT)
|
| IP Header |
Source Address |
SV_NETY |
| Destination Address |
NUT_NETZ |
| UDP Header |
Src Port |
53 |
| Dst Port |
Same as 1st Packet's Src Port |
| DNS Header |
ID |
Same as 1st Packet's ID |
| QR |
1 |
| OPCODE |
0 |
| AA |
1 |
| TC |
0 |
| RD |
Same as 1st Packet's RD |
| RA |
0 |
| Z |
0 |
| RCODE |
0 |
| QDCOUNT |
1 |
| ANCOUNT |
0 |
| NSCOUNT |
1 |
| ARCOUNT |
0 |
| DNS Question section |
QNAME |
A.example.com |
| QTYPE |
1 (0x0001) |
| QCLASS |
IN (0x0001) |
| DNS Authority section |
NAME |
example.com (Pointer 0xC00E) |
| TYPE |
SOA (0x0006) |
| CLASS |
IN (0x0001) |
| TTL |
15 |
| RDLENGTH |
33 |
| MNAME |
NS1.example.com (NS1 + Pointer 0xC00E) |
| RNAME |
root.example.com (root + Pointer 0xC00E) |
| SERIAL |
2005080300 |
| REFRESH |
1 hour |
| RETRY |
15 minutes |
| EXPIRE |
1 week |
| MINIMUM |
15 |
3rd Packet
|
4. Standard query from DNS Client1 (NUT) to DNS Server1 (TN)
|
| IP Header |
Source Address |
NUT_NETZ |
| Destination Address |
SV_NETY |
UDP Header
|
Src Port
|
any
|
Dst Port
|
53
|
DNS Header
|
ID |
any |
QR
|
0
|
OPCODE
|
0
|
AA
|
any
|
| TC |
0 |
| RD |
any |
RA
|
any
|
Z
|
any
|
RCODE
|
any
|
QDCOUNT
|
1
|
ANCOUNT
|
0
|
NSCOUNT
|
0
|
ARCOUNT
|
any
|
DNS Question section
|
QNAME |
A.example.com
|
QTYPE
|
A (0x0001)
|
QCLASS
|
IN (0x0001)
|
NUT_NETZ : DNS Client1(NUT)'s address
SV_NETY : DNS Server1(TN)'s address
1. Received standard query QNAME=A.example.com from NUT.
3. Received standard query QNAME=A.example.com from NUT.
If NUT has cache function, clear the cache.
RFC2308 Negative Caching of DNS Queries (DNS NCACHE)
5 - Caching Negative Answers