ping命令


Linux系統的ping命令是常用的網路命令,它通常用來測試與目標主機的連通性,我們經常會說「ping一下某機器,看是不是開著」、不能開啟網頁時會說「先ping閘道器地址192.168.1.1試試」。它通過傳送ICMP ECHO_REQUEST資料包到網路主機(send ICMP ECHO_REQUEST to network hosts),並顯示響應情況,這樣就可以根據它輸出的資訊來確定目標主機是否可存取(但這不是絕對的)。有些伺服器為了防止通過ping探測到,通過防火牆設定了禁止ping或者在核心引數中禁止ping,這樣就不能通過ping確定該主機是否還處於開啟狀態。
linux下的ping命令和windows下的ping執行稍有區別,linux下ping不會自動終止,需要按ctrl+c終止或者用引數-c指定要求完成的回應次數。

1.命令格式

ping [引數] [主機名或IP地址]

2.命令功能

ping命令用於:確定網路和各外部主機的狀態;跟蹤和隔離硬體和軟體問題;測試、評估和管理網路。如果主機正在執行並連在網上,它就對回送信號進行響應。每個回送信號請求包含一個網際協定(IP)和 ICMP 頭,後面緊跟一個 tim 結構,以及來填寫這個資訊包的足夠的位元組。預設情況是連續傳送回送信號請求直到接收到中斷信號(Ctrl-C)。
ping 命令每秒傳送一個資料報並且為每個接收到的響應列印一行輸出。ping 命令計算信號往返時間和(資訊)包丟失情況的統計資訊,並且在完成之後顯示一個簡要總結。ping 命令在程式超時或當接收到 SIGINT 信號時結束。Host 引數或者是一個有效的主機名或者是因特網地址。

3.命令引數

  • -d 使用Socket的SO_DEBUG功能。
  • -f 極限檢測。大量且快速地送網路封包給一台機器,看它的回應。
  • -n 只輸出數值。
  • -q 不顯示任何傳送封包的資訊,只顯示最後的結果。
  • -r 忽略普通的Routing Table,直接將資料包送到遠端主機上。通常是檢視本機的網路介面是否有問題。
  • -R 記錄路由過程。
  • -v 詳細顯示指令的執行過程。
  • -c 數目:在傳送指定數目的包後停止。
  • -i 秒數:設定間隔幾秒送一個網路封包給一台機器,預設值是一秒送一次。
  • -I 網路介面:使用指定的網路介面送出資料包。
  • -l 前置載入:設定在送出要求資訊之前,先行發出的資料包。
  • -p 範本樣式:設定填滿資料包的範本樣式。
  • -s 位元組數:指定傳送的資料位元組數,預設值是56,加上8位元組的ICMP頭,一共是64ICMP資料位元組。
  • -t 存活數值:設定存活數值TTL的大小。

4.使用範例

範例1:ping的通的情況

命令:

ping 192.168.0.5

輸出:

[yiibai@localhost ~]$ ping 192.168.0.5
PING 192.168.0.5 (192.168.0.5) 56(84) bytes of data.
64 bytes from 192.168.0.5: icmp_seq=1 ttl=64 time=0.498 ms
64 bytes from 192.168.0.5: icmp_seq=2 ttl=64 time=0.384 ms
64 bytes from 192.168.0.5: icmp_seq=3 ttl=64 time=0.486 ms
64 bytes from 192.168.0.5: icmp_seq=4 ttl=64 time=0.482 ms
^C
--- 192.168.0.5 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3006ms
rtt min/avg/max/mdev = 0.384/0.462/0.498/0.050 ms
[yiibai@localhost ~]$

範例2:ping不通的情況

命令:

ping 192.168.0.202

輸出:

[yiibai@localhost ~]$ ping 192.168.0.202
PING 192.168.0.202 (192.168.0.202) 56(84) bytes of data.
From 192.168.0.197 icmp_seq=1 Destination Host Unreachable
From 192.168.0.197 icmp_seq=2 Destination Host Unreachable
From 192.168.0.197 icmp_seq=3 Destination Host Unreachable
From 192.168.0.197 icmp_seq=4 Destination Host Unreachable
From 192.168.0.197 icmp_seq=5 Destination Host Unreachable
From 192.168.0.197 icmp_seq=6 Destination Host Unreachable
^C
--- 192.168.0.202 ping statistics ---
7 packets transmitted, 0 received, +6 errors, 100% packet loss, time 6023ms
pipe 4
[yiibai@localhost ~]$

範例3:ping閘道器

命令:

ping -b 192.168.0.0

輸出:

[yiibai@localhost ~]$ route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         gateway         0.0.0.0         UG    100    0        0 ens33
192.168.0.0     0.0.0.0         255.255.255.0   U     100    0        0 ens33
[yiibai@localhost ~]$ ping -b 192.168.0.0
WARNING: pinging broadcast address
PING 192.168.0.0 (192.168.0.0) 56(84) bytes of data.

範例4:ping指定次數

命令:

ping -c 10 www.baidu.com

輸出:

[yiibai@localhost ~]$ ping -c 10 www.baidu.com
PING www.baidu.com (14.215.177.38) 56(84) bytes of data.
64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=1 ttl=56 time=11.8 ms
64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=2 ttl=56 time=12.4 ms
64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=3 ttl=56 time=13.3 ms
64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=4 ttl=56 time=12.2 ms
64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=5 ttl=56 time=11.7 ms
64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=6 ttl=56 time=12.8 ms
64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=7 ttl=56 time=17.6 ms
64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=8 ttl=56 time=12.7 ms
64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=9 ttl=56 time=12.2 ms
64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=10 ttl=56 time=12.1 ms

--- www.baidu.com ping statistics ---
10 packets transmitted, 10 received, 0% packet loss, time 9078ms
rtt min/avg/max/mdev = 11.782/12.942/17.696/1.644 ms
[yiibai@localhost ~]$

說明: ping 百度(www.baidu.com) 10 次後自動退出。

範例5:時間間隔和次數限制的ping

命令:

ping -c 10 -i 0.5 www.tw511.com

輸出:

[yiibai@localhost ~]$ ping -c 10 -i 0.5 www.tw511.com
PING www.tw511.com (112.124.103.85) 56(84) bytes of data.
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=1 ttl=55 time=45.7 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=2 ttl=55 time=45.6 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=3 ttl=55 time=46.1 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=4 ttl=55 time=45.4 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=5 ttl=55 time=45.8 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=6 ttl=55 time=46.1 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=7 ttl=55 time=46.1 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=8 ttl=55 time=45.3 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=9 ttl=55 time=45.3 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=10 ttl=55 time=45.5 ms

--- www.tw511.com ping statistics ---
10 packets transmitted, 10 received, 0% packet loss, time 4531ms
rtt min/avg/max/mdev = 45.301/45.729/46.187/0.339 ms
[yiibai@localhost ~]$

說明: 每隔 0.5 秒的時間間隔,ping www.tw511.com ,到達 10 次數後退出。

範例6:通過域名ping公網上的站點

命令:

ping -c 5 www.tw511.com

輸出:

[yiibai@localhost ~]$ ping -c 5 www.tw511.com
PING www.tw511.com (112.124.103.85) 56(84) bytes of data.
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=1 ttl=55 time=45.6 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=2 ttl=55 time=45.9 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=3 ttl=55 time=46.1 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=4 ttl=55 time=45.3 ms
64 bytes from 112.124.103.85 (112.124.103.85): icmp_seq=5 ttl=55 time=46.1 ms

--- www.tw511.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4017ms
rtt min/avg/max/mdev = 45.332/45.848/46.166/0.413 ms
[yiibai@localhost ~]$ ping -c 5 www.studyoracle.cn
PING www.studyoracle.cn (123.57.223.216) 56(84) bytes of data.
64 bytes from 123.57.223.216 (123.57.223.216): icmp_seq=1 ttl=53 time=54.3 ms
64 bytes from 123.57.223.216 (123.57.223.216): icmp_seq=2 ttl=53 time=54.1 ms
64 bytes from 123.57.223.216 (123.57.223.216): icmp_seq=3 ttl=53 time=53.9 ms
64 bytes from 123.57.223.216 (123.57.223.216): icmp_seq=4 ttl=53 time=54.4 ms
64 bytes from 123.57.223.216 (123.57.223.216): icmp_seq=5 ttl=53 time=54.0 ms

--- www.studyoracle.cn ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4034ms
rtt min/avg/max/mdev = 53.981/54.184/54.438/0.232 ms
[yiibai@localhost ~]$

範例7:多引數使用

命令:

ping -i 3 -s 1024 -t 255 192.168.0.5

輸出:

[yiibai@localhost ~]$ ping -i 3 -s 1024 -t 255 192.168.0.5
PING 192.168.0.5 (192.168.0.5) 1024(1052) bytes of data.
1032 bytes from 192.168.0.5: icmp_seq=1 ttl=64 time=0.644 ms
1032 bytes from 192.168.0.5: icmp_seq=2 ttl=64 time=1.36 ms
1032 bytes from 192.168.0.5: icmp_seq=3 ttl=64 time=0.377 ms
1032 bytes from 192.168.0.5: icmp_seq=4 ttl=64 time=1.45 ms
1032 bytes from 192.168.0.5: icmp_seq=5 ttl=64 time=1.46 ms
1032 bytes from 192.168.0.5: icmp_seq=6 ttl=64 time=1.45 ms
^C
--- 192.168.0.5 ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 15038ms
rtt min/avg/max/mdev = 0.377/1.125/1.468/0.444 ms
[yiibai@localhost ~]$

說明:-i 3 傳送週期為 3 秒, -s 設定傳送包的大小為1024-t 設定TTL值為 255