5 ms·
This isn’t a gab at you. But this question doesn’t make sense. I think the things you don’t know you don’t know about TCP and distributed system design make thi
by vlan0 4y ago
This isn’t a gab at you. But this question doesn’t make sense. I think the things you don’t know you don’t know about TCP and distributed system design make this difficult to pick apart.
Remember, your identity in a TCP connection is your IP address. If you connect from another IP and want your session to continue, identity must be handled higher in the stack.
TCP connection technically live forever by default. It’s up to either party to complete the handshake. Without that mechanism, your box would run out of ports.
- topspin 4y ago> Remember, your identity in a TCP connection is your IP address The essential tuple of a stateful IP session, the "5-tuple," is the source IP address, source port number, destination IP address, destination port number and the IP protocol number, in this case TCP. None of those elements can change during the lifetime of the connection. Or rather, changing any element constitutes a different connection. Not that you needed to be told that; you probably know this already. It's just an interesting factoid that I imagine others might find interesting or useful when thinking about networking. In the guts of every device that handles TCP state (clients, servers, middle boxes, whatever) there is a table of all in-flight 5-tuples that marries every incoming packet with some state.
- remram 4y agoPort numbers are not an IP concept. "IP session"?
- mrkstu 4y agoMost protocols atop IP have the concept of ports- i.e. TCP or UDP.
- vlan0 4y agoIndeed! I always appreciate help explaining. I've been deep in networking for so long that I struggle threading the needle between not enough and too much information.