Question

how can the IPv4 is unreliable even though it provides a checksum?

what is the time to live for Windows and Linux?  to see if they are different or not

Answer 1

Detailed simple explanation has been provided for both the questions please go through them thoroughly.

Thank You.

Before I answer the question let us see the terms

Reliable: In reliable connection source will be aware of the packets reached to destination.

Ex: When Source sends a packet. Destination sends acknowledgement to source about that particular received packet.

Checksum : This is used to verify the data received. It is a Error detecting technique while transferring data.

By now seeing both you might have understood the difference between reliability and error detection technique.

Though IP V4 provides a checksum it does not provide any technique to covey the source that packet has been received by destination.

hence IPv4 is not a reliable connection though it has the checksum.

Let us see the second question:

In windows 10 Time To Live (TTL ): 128

In Linux Time To Live (TTL): 64

Though these values are not fixed based on the versions values are modified . To know the TTL of your own system perform following steps

1. open CMD (command prompt)
2. Type 'ping 127.0.0.1'

3. See the result

TTL value will be displayed.