ping

C:\Users\sas>ping

用法: ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS]
[-r count] [-s count] [[-j host-list] | [-k host-list]]
[-w timeout] [-R] [-S srcaddr] [-c compartment] [-p]
[-4] [-6] target_name

選項:
-t Ping 指定的主機，直到中止。
若要查看統計信息並繼續操做，請鍵入 Ctrl+Break；
若要中止，請鍵入 Ctrl+C。
-a 將地址解析爲主機名。
-n count 要發送的回顯請求數。
-l size 發送緩衝區大小。
-f 在數據包中設置「不分段」標記(僅適用於 IPv4)。
-i TTL 生存時間。
-v TOS 服務類型(僅適用於 IPv4。該設置已被棄用，
對 IP 標頭中的服務類型字段沒有任何
影響)。
-r count 記錄計數躍點的路由(僅適用於 IPv4)。
-s count 計數躍點的時間戳(僅適用於 IPv4)。
-j host-list 與主機列表一塊兒使用的鬆散源路由(僅適用於 IPv4)。
-k host-list 與主機列表一塊兒使用的嚴格源路由(僅適用於 IPv4)。
-w timeout 等待每次回覆的超時時間(毫秒)。
-R 一樣使用路由標頭測試反向路由(僅適用於 IPv6)。
根據 RFC 5095，已棄用此路由標頭。
若是使用此標頭，某些系統可能丟棄
回顯請求。
-S srcaddr 要使用的源地址。
-c compartment 路由隔離艙標識符。
-p Ping Hyper-V 網絡虛擬化提供程序地址。
-4 強制使用 IPv4。
-6 強制使用 IPv6。

C:\Users\sas>

 

 

https://www.lifewire.com/definition-of-ping-817864

 

Ping is the name of a standard software utility used to test network connections. It can be used to determine if a remote device—such as a website or game server—can be reached across the network and if so, the connection's latency.

Ping tools are part of Windows, macOS, Linux, and some routers and game consoles. You can download other ping tools from third-party developers and use the tools on phones and tablets.

 

Note: Computer enthusiasts also use the term "ping" colloquially when initiating contact with another person via email, instant message, or other online tools. In that context, though, the word "ping" just means to notify, usually briefly.

Ping Tools

Most ping utilities and tools use Internet Control Message Protocol (ICMP). They send request messages to a target network address at periodic intervals and measure the time it takes for a response message to arrive.

These tools typically support options such as:

• How many times to send requests.
• How large of a request message to send.
• How long to wait for each reply.

The output of ping varies depending on the tool. Standard results include:

• IP address of the responding computer.
• Length of time in milliseconds between sending the request and receiving the response.
• An indication of the number of network hops between the requesting and responding computers.

 

• Error messages if the target computer did not respond.

Where to Find Ping Tools

When using ping on a computer, there are ping commands that work with Command Prompt in Windows.

One tool called Ping works on iOS to ping any URL or IP address. It gives the total packets sent, received, and lost, as well as the minimum, maximum, and average time that it took to receive a response.

 

A different app named Ping, but for Android, can perform similar functions.

What Is the Ping of Death?

In late 1996 and early 1997, a flaw in the implementation of networking in some operating systems became well-known and popularized by hackers as a way to remotely crash computers. The "Ping of Death" attack was relatively easy to carry out and dangerous due to its high probability of success.

Technically speaking, the Ping of Death attack involved sending IP packets of a size greater than 65,535 bytes to the target computer. IP packets of this size are illegal, but a programmer can build applications capable of creating them.

Carefully programmed operating systems could detect and safely handle illegal IP packets, but some failed to do so. ICMP ping utilities often included large-packet capability and became the namesake of the problem, although UDP and other IP-based protocols also could transport the Ping of Death.

Operating system vendors quickly devised patches to avoid the Ping of Death, which no longer poses a threat to today's computer networks. Still, many websites have kept the convention of blocking ICMP ping messages at their firewalls to avoid similar denial of service attacks.