TCP / HTTP Listening On Ports: How Can Many Users Share the Same Port So, what happens when a server listen for incoming connections on a TCP port? For example, let’s say you have a web-server on port 80. Let’s assume that your computer has the public IP address of 24.14.181.229 and the person that … Read more
When you send bytes from a buffer with a normal TCP socket, the send function returns the number of bytes of the buffer that were sent. If it is a non-blocking socket or a non-blocking send then the number of bytes sent may be less than the size of the buffer. If it is a … Read more
Well, the most likely difference is that you still have to do an actual lookup of localhost somewhere. If you use 127.0.0.1, then (intelligent) software will just turn that directly into an IP address and use it. Some implementations of gethostbyname will detect the dotted format (and presumably the equivalent IPv6 format) and not do … Read more
To answer your questions. Even though they achieve (in general) similar things, yes, they are really different. WebSockets typically run from browsers connecting to Application Server over a protocol similar to HTTP that runs over TCP/IP. So they are primarily for Web Applications that require a permanent connection to its server. On the other hand, … Read more
AF_INET is an address family that is used to designate the type of addresses that your socket can communicate with (in this case, Internet Protocol v4 addresses). When you create a socket, you have to specify its address family, and then you can only use addresses of that type with the socket. The Linux kernel, … Read more
The answer differs depending on what OS is being considered. In general though: For TCP, no. You can only have one application listening on the same port at one time. Now if you had 2 network cards, you could have one application listen on the first IP and the second one on the second IP … Read more
It’s fatal. The remote server has sent you a RST packet, which indicates an immediate dropping of the connection, rather than the usual handshake. This bypasses the normal half-closed state transition. I like this description: “Connection reset by peer” is the TCP/IP equivalent of slamming the phone back on the hook. It’s more polite than … Read more