I am trying to connect two workstations (CentOS 3&4) directly using a straight through cat 5e cable with a crossover adapter on one of the ends. Both hosts have gigabit-capable ethernet card. According to lspci host 1 has: 03:0e.0 Ethernet controller: Intel Corporation 82545EM Gigabit Ethernet Controller (Copper) (rev 01) and host 2 has: 05:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8050 Gigabit Ethernet Controller (rev 17) In order to get this controller work on host 2, I had to download and install a more recent version of the sk98lin driver. Host 2 runs CentOS 4. Host 1 runs CentOS 3 (with a stock e1000 driver). After I setup networking, ethtool reported for both hosts that the link runs at 100Mbps even though it says in both cases that the capability for 1000baseT/Half 1000baseT/Full modes and exists and is being advertised. If I force 1000Mbps speed with "ethtool -s eth1 speed 1000", I get: # ethtool eth1 Settings for eth1: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 1000baseT/Half 1000baseT/Full Advertised auto-negotiation: No Speed: Unknown! (65535) Duplex: Unknown! (255) Port: Twisted Pair PHYAD: 0 Transceiver: internal Auto-negotiation: on Supports Wake-on: g Wake-on: g and the eth1 link stops working. What could be a problem here? I tried loading both drivers with the parameter for 1000Mbps speed parameters but that didn't help. ( I used on host 1, alias eth1 e1000 Speed=1000 host 2, alias eth1 sk98lin Speed_A=1000 Speed_B=1000) -akop