Yes. It is possible.

If you make software that uses the socket communication by your self, it is possible to connect multiple devices by distinguishing by IP addresses.

If you use COM port redirector (the driver that supports Ethernet as virtual COM port), it is possible to set multiple virtual COM ports.

(The connectable number differs by the spec. of PC, the availability of a memory, etc.)

In addition, COM port redirector cannot check the control line information of RS-232C side.