最近在寫tcp/ip的下位機，所以學(xué)了不少關(guān)于網(wǎng)絡(luò)和協(xié)議的東西。總體上來說，很復(fù)雜。不過還是有據(jù)可循的。
這是通過wireshark抓包得到的
這是一個簡單的ping命令，得到的數(shù)據(jù)。
Frame 207: 74 bytes on wire (592 bits), 74 bytes captured (592 bits) 線路上傳輸了74字節(jié)，實際接收74個字節(jié)
Arrival Time: Jan 1, 2000 08:09:10.326362000 中國標(biāo)準(zhǔn)時間 時間
Epoch Time: 946685350.326362000 seconds 包間隔時間
Time delta from previous captured frame: 0.087277000 seconds
Time delta from previous displayed frame: 0.087277000 seconds
Time since reference or first frame: 12.473428000 seconds
Frame Number: 207
Frame Length: 74 bytes (592 bits) 幀長度
Capture Length: 74 bytes (592 bits) 捕獲長度
Frame is marked: False
Frame is ignored: False
Protocols in frame: eth:ip:icmp:data 協(xié)議層級
Coloring Rule Name: ICMP 包含協(xié)議
Coloring Rule String: icmp || icmpv6
Ethernet II, Src: D-Link_60:3b:42 (f0:7d:68:60:3b:42), Dst: Tp-LinkT_4f:6f:f2 (94:0c:6d:4f:6f:f2)
源mac地址 目標(biāo)mac地址
Destination: Tp-LinkT_4f:6f:f2 (94:0c:6d:4f:6f:f2)
Address: Tp-LinkT_4f:6f:f2 (94:0c:6d:4f:6f:f2)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
. ... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
Type: IP (0x0800) ip類型
Internet Protocol, Src: 192.168.1.111 (192.168.1.111), Dst: 192.168.1.1 (192.168.1.1)
源ip地址 目標(biāo)ip地址
Version: 4 版本號
Header length: 20 bytes 頭字節(jié)長度
Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00) 差分服務(wù)字段
0000 00.. = Differentiated Services Codepoint: Default (0x00)
.... ..0. = ECN-Capable Transport (ECT): 0
.... ...0 = ECN-CE: 0
Total Length: 60 IP包長度
Identification: 0x31e7 (12775) 標(biāo)志字段 不一樣，具體為什么不知道
Flags: 0x00 標(biāo)記字段
Fragment offset: 0 分段偏移
Time to live: 64 生存期
Protocol: ICMP (1) 包內(nèi)封裝協(xié)議
Header checksum: 0xc519 [correct] 頭校驗
Source: 192.168.1.111 (192.168.1.111) 源ip
Destination: 192.168.1.1 (192.168.1.1) 目標(biāo)ip
Internet Control Message Protocol
Type: 8 (Echo (ping) request) 類型：請求
Code: 0 代碼：0
Checksum: 0x495c [correct] 校驗
Identifier: 0x0300 標(biāo)識碼
Sequence number: 256 (0x0100) 序列碼，應(yīng)該是ping一次加一次
Sequence number (LE): 1 (0x0001)
Data (32 bytes) 數(shù)據(jù)
Data: 6162636465666768696a6b6c6d6e6f707172737475767761...
Length: 32
源mac地址 目標(biāo)mac地址 ip類型 版本與字節(jié)數(shù)
94 0c 6d 4f 6f f2 f0 7d 68 60 3b 42 08 00 45 00
Ip包長 標(biāo)志段 標(biāo)記 偏移 生存期 icmp包 頭檢驗 源ip
00 3c 31 e7 00 00 40 01 c5 19 c0 a8 01 6f
目標(biāo)ip 類型 校驗 標(biāo)識碼 序列碼 數(shù)據(jù)
c0 a8 01 01 08 00 49 5c 03 00 01 00 61 62 63 64 65 66
67 68 69 6a 6b 6c 6d 6e 6f 70 71 72 73 74 75 76
77 61 62 63 64 65 66 67 68 69