000 00 00 BA 5E BA 11 00 A0 C9 B0 5E BD 08 00 45 00 …^……^…E.

010 05 DC 1D E4 40 00 7F 06 C2 6D 0A 00 00 02 0A 00 ….@….m……

020 01 C9 00 50 07 75 05 D0 00 C0 04 AE 7D F5 50 10 …P.u……}.P.

030 70 79 8F 27 00 00 48 54 54 50 2F 31 2E 31 20 32 py.’..HTTP/1.1.2

040 30 30 20 4F 4B 0D 0A 56 69 61 3A 20 31 2E 30 20 00.OK..Via:.1.0.

050 53 54 52 49 44 45 52 0D 0A 50 72 6F 78 79 2D 43 STRIDER..Proxy-C

060 6F 6E 6E 65 63 74 69 6F 6E 3A 20 4B 65 65 70 2D onnection:.Keep-

070 41 6C 69 76 65 0D 0A 43 6F 6E 74 65 6E 74 2D 4C Alive..Content-L

080 65 6E 67 74 68 3A 20 32 39 36 37 34 0D 0A 43 6F ength:.29674..Co

090 6E 74 65 6E 74 2D 54 79 70 65 3A 20 74 65 78 74 ntent-Type:.text

0A0 2F 68 74 6D 6C 0D 0A 53 65 72 76 65 72 3A 20 4D /html..Server:.

0B0 69 63 72 6F 73 6F 66 74 2D 49 49 53 2F 34 2E 30 ..Microsoft

0C0 0D 0A 44 61 74 65 3A 20 53 75 6E 2C 20 32 35 20 ..Date:.Sun,.25.

0D0 4A 75 6C 20 31 39 39 39 20 32 31 3A 34 35 3A 35 Jul.1999.21:45:5

0E0 31 20 47 4D 54 0D 0A 41 63 63 65 70 74 2D 52 61 1.GMT..Accept-Ra

0F0 6E 67 65 73 3A 20 62 79 74 65 73 0D 0A 4C 61 73 nges:.bytes..Las

100 74 2D 4D 6F 64 69 66 69 65 64 3A 20 4D 6F 6E 2C t-Modified:.Mon,

110 20 31 39 20 4A 75 6C 20 31 39 39 39 20 30 37 3A .19.Jul.1999.07:

120 33 39 3A 32 36 20 47 4D 54 0D 0A 45 54 61 67 3A 39:26.GMT..ETag:

130 20 22 30 38 62 37 38 64 33 62 39 64 31 62 65 31 .”08b78d3b9d1be1

140 3A 61 34 61 22 0D 0A 0D 0A 3C 74 69 74 6C 65 3E :a4a”….<title>

150 53 6E 69 66 66 69 6E 67 20 28 6E 65 74 77 6F 72 Sniffing.(networ

160 6B 20 77 69 72 65 74 61 70 2C 20 73 6E 69 66 66 k.wiretap,.sniff

170 65 72 29 20 46 41 51 3C 2F 74 69 74 6C 65 3E 0D er).FAQ</title>.

180 0A 0D 0A 3C 68 31 3E 53 6E 69 66 66 69 6E 67 20 …<h1>Sniffing.

190 28 6E 65 74 77 6F 72 6B 20 77 69 72 65 74 61 70 (network.wiretap

1A0 2C 20 73 6E 69 66 66 65 72 29 20 46 41 51 3C 2F ,.sniffer).FAQ</

1B0 68 31 3E 0D 0A 0D 0A 54 68 69 73 20 64 6F 63 75 h1>….This.docu

1C0 6D 65 6E 74 20 61 6E 73 77 65 72 73 20 71 75 65 ment.answers.que

1D0 73 74 69 6F 6E 73 20 61 62 6F 75 74 20 74 61 70 stions.about.tap

1E0 70 69 6E 67 20 69 6E 74 6F 20 0D 0A 63 6F 6D 70 ping.into…comp

1F0 75 74 65 72 20 6E 65 74 77 6F 72 6B 73 20 61 6E uter.networks.an

This packet was taken from a packet sniffer that monitors a Web server.

This packet was originally 1514 bytes long, but only the first 512 bytes are shown here. This is the standard hexdump representation of a network packet, before being decoded. A hexdump has three columns: the offset of each line, the hexadecimal data, and the ASCII equivalent. This packet contains a 14-byte Ethernet header, a 20-byte IP header, a 20-byte TCP header, an HTTP header ending in two line-feeds (0D 0A 0D 0A) and then the data.

By examining the packet identify the name and version of the Web server?

A.
Apache 1.2

B.
IIS 4.0

C.
IIS 5.0

D.
Linux WServer 2.3

Explanation:
We see that the server is Microsoft, but the exam designer didn’t want to make it easy for you. So what they did is blank out the IIS 4.0. The key is in line “0B0” as you see:

0B0 69 63 72 6F 73 6F 66 74 2D 49 49 53 2F 34 2E 30 ..Microsoft

49 is I, so we get II
53 is S, so we get IIS
2F is a space
34 is 4
2E is .
30 is 0
So we get IIS 4.0

The answer is B

If you don’t remember the ASCII hex to Character, there are enough characters and numbers already converted. For example, line “050” has STRIDER which is 53 54 52 49 44 45 52 and gives you the conversion for the “I:” and “S” characters (which is “49” and “53”).