Hi Eric, On 26.03.20 18:58, Eric Robinson wrote: > Greetings, > > Many people say the maximum number of client ports is 64K. However, TCP > connections only require unique sockets, which are defined as... > > local_IP:local_port -> remote_ip:remote_port > > Theoretically, it is possible for a client process to keep using the same > local source port, as long as the connections are to a unique destinations. > For example on a local machine, the following connections should be > possible... > > 192.168.5.100:1400 -> 192.168.5.200:3306 > 192.168.5.100:1400 -> 192.168.5.201:3306 > 192.168.5.100:1400 -> 192.168.5.202:3306 > 192.168.5.100:1400 -> 192.168.5.203:3306 > > I've seen this demonstrated successfully here: > > https://serverfault.com/questions/326819/does-the-tcp-source-port-have-to-be-unique-per-host > > As someone on that page pointed out, while it is possible, it does not > commonly occur in practice "because most TCP APIs don't provide a way to > create more than one connection with the same source port, unless they have > different source IP addresses." This leads to the 64K maximum client port > range, but it is really a limitation of the APIs, not TCP. > > So how does tomcat handle things? Is it limited to a maximum 64K client > source ports, or is it 64K per destination, as it should be?
To be honest, I can't remember to have seen a web- or application server that accepts 64K concurrent connections at all, let alone to a single client. I can't come up with any reason to do so, I'd assume that there's a DOS attack if I get 100 concurrent incoming connections from a single IP, and a programming error if the server sets up more than 1K outgoing connections Maybe I'm missing the obvious, or have only administered meaningless installations, but I fail to see the real world relevance of this question. --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
