DNS MESSAGE EXAMPLE

SEND

7E FF 03 00 21 45 00 00 40 00 02 00 00 3C 11 E0 30 CE D9 8F 1F C7 B6 78 CB 04 6D 00 35 00 2C 0D 54 00 02 01 00 00 01 00 00 00 00 00 00 04 70 6F 70 64 02 69 78 06 6E 65 74 63 6F 6D 03 63 6F 6D 00 00 01 00 01 C7 00 7E

Start 7E

Address FF 03
SEP 00 21

IP Header 45 00 00 40 00 02 00 00 3C 11 E0 30 CE D9 8F 1F C7 B6 78 CB 04 6D

UDP Header 00 35 00 2C 0D 54

DNS Header 00 02 01 00 00 01 00 00 00 00 00 00

DNS Message 04 70 6F 70 64 02 69 78 06 6E 65 74 63 6F 6D 03 63 6F 6D 00 00 01 00 01

FCS C7 00

Stop 7E

IP Header
VER=4 IHL=5 TOS=0 TOL=64 ID=2 FLG=00 FRO=00 TTL=60 PRO=17 IP_SUM=E030 SRC=206.217.143.31. DEST=199.182.120.203. OPT=00000000

UDP Header
SRC_PORT=046D

DEST_PORT=0035

UDP_LEN=002C

UDP_SUM=0D54

DNS Header
ID=2 QR=0 OPCODE=0 AA = 0 TC=0 RD = 1 RA=0 Z =0 RCCODE=0 QDCOUNT=1 ANCOUNT=0 NSCOUNT=0 ARCOUNT=0

DNS Message
QNAME=04 70 6F 70 64 02 69 78 06 6E 65 74 63 6F 6D 03 63 6F 6D 00 QTYPE=0001 QCLASS=0001

Client sends a UDP/IP packet with a DNS question (QR=0) as a standard query (OPCODE=0) with one entry (QDCOUNT=1). It does not include any resource in neither one of the answer, authority or additional records (ANCOUNT=0 NSCOUNT=0 ARCOUNT=0). The QNAME specifies the domain name of the resource the client is searching for (QNAME = popd.ix.netcom.com.). Note that the periods in the domain name are replaced by the length of the name that follows. The type and class of resource the client is searching for are QTYPE=1 (Host Address), QCLASS=1 (Internet).