往返时间（RTT）和生存时间（TTL）之间的差异

1.往返时间(RTT) ：
数据包要发送到目的地所花费的时间长度，包括确认数据包在原始位置被接收所花费的时间。

该图显示了RTT

2.生存时间(TTL)：
正在发送的数据的寿命或寿命。在指定的时间结束或经过之后，数据将被丢弃。
或者也可以将数据包设置为在网络中存在的跃点数，之后将该数据包丢弃。 TTL字段的目的是避免无法传递的数据报在网络中不断流通的情况。

往返时间和生存时间之间的差异：

S.No	Round trip time	Time to live
1	Also known as ping time.	Also known as hop limit.
2	Gives the total time taken to send data packet and to get an acknowledgment back from the destination.	Gives the hop limit to travel in the network path. after that limit the packet will be discarded.
3	It is an important for determining the connection on a local network or the larger Internet network, and used to diagnose the speed and reliability of network connections.	Helps us to prevent the data packet from circulating indefinitely in the routers path.
4	The round trip time is not stored anywhere, it will be calculated when the acknowledgement comes from destination.	It is an 8-bit field stored in IP header.
5	It can be any value, because it depends on many factors.	Maximum value that can be set to TTL is 255 since its the maximum value that we can produce with 8-bits.
6	It depends on many factors like distance, no. of hops, server response time etc.	It depends on system, It is set initially by the system which is sending the packet.
7	RTT is measured in milliseconds.	TTL is measured in seconds.

如何找到RTT和TTL?

例子1. ping amazon.com

我们可以使用ping命令找到RTT和TTL。打开您的终端或命令提示符，然后键入以下命令以查看RTT和TTL到amazon.com

ping amazon.com

您将看到与此类似的屏幕。

每行以单词Reply开头的行是服务器对客户端发送的数据包的答复。在上面的示例中，我们收到4个答复，这意味着我们发送了4个数据包。
用红色框标记的值是RTT(往返时间) ，以毫秒为单位显示，因为它以毫秒为单位
蓝色框标记的值为TTL(生存时间)，以秒为单位。

因此，以上ping的平均RTT为(230 + 231 + 236 + 230)/ 4 = 231.75毫秒
ping以上的TTL为235秒或235跳

例子2. ping google.com

在以下命令的帮助下ping google.com

ping google.com

运行上述命令后，您将看到类似于此的屏幕

ping google.com

因此，以上ping的平均RTT为(48 + 62 + 56 + 44)/ 4 = 52.5 ms
ping以上的TTL为114秒或114跳。