June 2016
Beginner to intermediate
376 pages
8h 58m
Japanese
Content preview from データ分析によるネットワークセキュリティ
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162
8
章 参照と検索：身元を確認するツール
8.2.3
接続性の検査：
ping
を使ったアドレスへの接続
接続性を検査するための最も基本的なコマンドラインツールはpingである。pingは、ICMPメッ
セージ（「2.2.1 パケットとフレームフォーマット」を参照）を使って動作する。pingは、ICMPエコー
リクエスト（種別8、コード0）を相手に送信する。相手はエコーリクエストメッセージを受信すると、
エコーリプライ（種別0、コード 0）で応答する。例8-1にpingの出力とその内容のpcapを示す。
例8-1 ping 出力
$ ping -c 1 nytimes.com
PING nytimes.com (170.149.168.130): 56 data bytes
64 bytes from 170.149.168.130: icmp_seq=0 ttl=252 time=29.388 ms
$ tcpdump -Xnr ping.pcap
rea
ding from file ping.pcap, link-type EN10MB (Ethernet)
20:38:09.074960 IP 192.168.1.12 > 170.149.168.130:
ICMP echo request, id 44854, seq 0, length 64
0x0000: 4500 0054 0942 0000 4001 5c9b c0a8 010c E..T.B..@.\.....
0x0010: ...
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