Simulate delayed and dropped packets on Linux

netem leverages functionality already built into Linux and userspace utilities to simulate networks. This is actually what Mark’s answer refers to, by a different name. The examples on their homepage already show how you can achieve what you’ve asked for: Examples Emulating wide area network delays This is the simplest example, it just adds a … Read more

What is the theoretical maximum number of open TCP connections that a modern Linux box can have

A single listening port can accept more than one connection simultaneously. There is a ’64K’ limit that is often cited, but that is per client per server port, and needs clarifying. Each TCP/IP packet has basically four fields for addressing. These are: source_ip source_port destination_ip destination_port <—– client ——> <——— server ————> Inside the TCP … Read more

How do multiple clients connect simultaneously to one port, say 80, on a server? [duplicate]

First off, a “port” is just a number. All a “connection to a port” really represents is a packet which has that number specified in its “destination port” header field. Now, there are two answers to your question, one for stateful protocols and one for stateless protocols. For a stateless protocol (ie UDP), there is … Read more

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)