Linux下wireshark抓包验证telnet明文传输密码

Host-A

IP：192.168.56.129 OS：RHEL5.9 32bit Service：telnet-server

Host-B

IP：192.168.56.128 OS：RHEL5.9 32bit Service：telnet-client

在HostA上查看网卡信息

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# ifconfig eht0
eth0 Link encap:Ethernet HWaddr 00:0C:29:CC:30:9A

inet addr:192.168.56.129 Bcast:192.168.56.255 Mask:255.255.255.0

inet6 addr: fe80::20c:29ff:fecc:309a/64 Scope:Link

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:4914 errors:0 dropped:0 overruns:0 frame:0

TX packets:3705 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000

RX bytes:2419811 (2.3 MiB) TX bytes:276508 (270.0 KiB)

Interrupt:67 Base address:0x2024

启动telnet服务

安装wireshark抓包工具

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#yum install -y wireshark
#yum install -y wireshark-gnome //把命令行工具和gnome图形工具的包一起安装上

开启wireshark抓包，为了方便分析包信息，写了过滤规则tcp.port == 23 and ip.dst == 192.168.56.129

在192.168.56.128机器上以root用户telnet登录192.168.56.129，首先查看网卡信息

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#ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:0C:29:E8:F9:FE

inet addr:192.168.56.128 Bcast:192.168.56.255 Mask:255.255.255.0

inet6 addr: fe80::20c:29ff:fee8:f9fe/64 Scope:Link

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:3518 errors:0 dropped:0 overruns:0 frame:0

TX packets:4232 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000

RX bytes:276736 (270.2 KiB) TX bytes:2356751 (2.2 MiB)

Interrupt:67 Base address:0x2024