20 auto-sensing 10/100/1000 ports (IEEE 802.3 Type 10Base-T, IEEE 802.3u Type 100Base-TX, IEEE 802.3ab Type 1000Base-T),Media Type: Auto-MDIX,Duplex: 10Base-T/100Base-TX: half or full; 1000Base-T: full only,2 CX4 10-GbE ports (IEEE 802.3ak Type 10Gbase-CX4),Duplex: full only,2 open 10-GbE X2 transceiver slots,1 RS-232C DB-9 console port,4 dual-personality ports,each port can be used as either an RJ-45 10/100/1000 port (IEEE 802.3 Type 10Base-T; IEEE 802.3u Type 100Base-TX; IEEE 802.3ab 1000Base-T Gigabit Ethernet) or an open mini-GBIC slot (for use with mini-GBIC transceivers)