在做项目的过程中，发现当指定server port比较大时，例如43500，这时在client与server建立socket的过程中，系统会分配一个与server port一样的端口给localport，这个时候传输数据等于自己发自己，请问localport和server port可以一样吗？这个难道是JDK的bug？

Born at the University of California, Berkeley, in the 1980s, sockets first appeared in the Unix world as the Berkeley Sockets Interface, a programming device designed to help far-flung networked ...

The two most common transport layer protocols are the transmission control protocol (TCP) and the user datagram protocol (UDP). One of the main differences between the two protocols is reliability.