Question

Can any one tell me the difference between TTL and Keep alive in sockets (C# Networking) and also Linger.. Thanks in advance.

Answer 1

TTL tells the packet how many routers he can go through before giving up, while Keep Alive tells the connexion how long it must be kept open without activity.

From what i read about Linger, i don’t see the difference with keep-alive, i may be missing something here.

EDIT: The linger option allows you to close the socket while telling it to wait some time to see if data is still on the wire; from this page, we read that

There may still be data available in the outgoing network buffer after
you close the Socket. If you want to specify the amount of time that
the Socket will attempt to transmit unsent data after closing, create
a LingerOption with the enabled parameter set to true, and the seconds
parameter set to the desired amount of time. The seconds parameter is
used to indicate how long you would like the Socket to remain
connected before timing out. If you do not want the Socket to stay
connected for any length of time after closing, create a LingerOption
with the enabled parameter set to false. In this case, the Socket will
close immediately and any unsent data will be lost. Once created, pass
the LingerOption to the Socket.SetSocketOption method. If you are
sending and receiving data with a TcpClient, then pass the
LingerOption to the TcpClient.LingerState method.