上网保护隐私（2）监控第三方应用的后台联网行为

情景：

我想使用第三方应用 simpleScreenRecorder 但是不清楚它会不会偷偷在联网传输我的数据。

步骤：

（1）以nat方式运行虚机ubuntu ，使用静态ip 192.168.43.103，并安装 simpleScreenRecorder

（2）在主机监听虚拟机ip 

sudo tcpdump src 192.168.43.103  -i 网桥

（3）启动被测应用ssr，观察监控结果

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on switch, link-type EN10MB (Ethernet), capture size 262144 bytes
11:59:12.160924 IP 192.168.43.103.47769 > 192.168.43.101.domain: 8843+ A? connectivity-check.ubuntu.com. (47)
11:59:12.167003 IP 192.168.43.103.44640 > is-content-cache-1.ps5.canonical.com.http: Flags [S], seq 1157285031, win 64240, options [mss 1460,sackOK,TS val 1278342437 ecr 0,nop,wscale 7], length 0
11:59:12.494455 IP 192.168.43.103.44640 > is-content-cache-1.ps5.canonical.com.http: Flags [.], ack 624587631, win 502, options [nop,nop,TS val 1278342764 ecr 1543864703], length 0
11:59:12.494832 IP 192.168.43.103.44640 > is-content-cache-1.ps5.canonical.com.http: Flags [P.], seq 0:88, ack 1, win 502, options [nop,nop,TS val 1278342764 ecr 1543864703], length 88: HTTP: GET / HTTP/1.1
11:59:12.816998 IP 192.168.43.103.44640 > is-content-cache-1.ps5.canonical.com.http: Flags [.], ack 190, win 501, options [nop,nop,TS val 1278343087 ecr 1543865051], length 0
11:59:12.817303 IP 192.168.43.103.44640 > is-content-cache-1.ps5.canonical.com.http: Flags [F.], seq 88, ack 190, win 501, options [nop,nop,TS val 1278343087 ecr 1543865051], length 0
11:59:12.820648 IP 192.168.43.103.44640 > is-content-cache-1.ps5.canonical.com.http: Flags [.], ack 191, win 501, options [nop,nop,TS val 1278343090 ecr 1543865051], length 0
11:59:17.457015 ARP, Reply 192.168.43.103 is-at 52:54:00:12:34:56 (oui Unknown), length 46
12:02:31.419313 IP 192.168.43.103.57212 > alphyn.canonical.com.ntp: NTPv4, Client, length 48
12:02:34.878866 IP 192.168.43.103.mdns > 224.0.0.251.mdns: 0 [2q] PTR (QM)? _ipps._tcp.local. PTR (QM)? _ipp._tcp.local. (45)
12:02:36.532175 ARP, Request who-has 192.168.43.101 tell 192.168.43.103, length 46
12:02:37.136989 ARP, Reply 192.168.43.103 is-at 52:54:00:12:34:56 (oui Unknown), length 46
12:02:42.137135 IP 192.168.43.103.46533 > 192.168.43.101.domain: 56946+ AAAA? connectivity-check.ubuntu.com. (47)