DB-60 connector is SERIAL interface, you cannot connect it to Ethernet port.
You may, depending on cable connected, use the interface as V.35, RS-232,
etc., but not Ethernet. Cisco 2507 router (if it's what you have), has
16-ports integrated Ethernet hub, but I believe logically they all appear as
one Ethernet interface.
CCNP, CCDP, CCSP, Cisco Voice, MCSE W2K, MCSE+I, Security+, etc.
CCIE R&S (in progress), CCIE Voice (in progress)
Headset Adapters for Cisco IP Phones