On Wed, 2006-01-25 at 22:22 -0500, nethub@xxxxxxxxx wrote:
> Akop Pogosian wrote:
> > 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)
> >
> Are you using a 1000 Mbps compatible crossover adapter? For 1000 Mbps
> to function, it needs two pairs to be crossed-over -- see
> http://www.cabling-design.com/references/pinouts/1000base_t_crossover.shtml
> for the proper pin layout. HTH.
The pinout shown on the above mentioned website crosses over all 4 pairs
compared to a standard crossover which only crosses over the green and
orange pairs (pins 1,2,3 and 6)
Our experience with GigE indicates that two hosts can communicate with a
straight-thru or standard crossover cable (2 pairs). Host-to-switch
cabling can be straight-thru or crossover as well.
The hardware in question is a Cisco 2960 and the Broadcom Corporation
NetXtreme BCM5704 Gigabit Ethernet (tg3 driver).
Bob...
