connecting to a hardwired ethernet device

[Geoffrey Leach]

On 10/02/2014 01:34:26 PM, Rick Stevens wrote:
> On 10/02/2014 01:24 PM, Geoffrey Leach issued this missive:
> > This is a new Fedora 19 install.
> >
> > The install correctly detected the ethernet port.
> >
> > ifconfig sees em1, and the configuration data is correct
> >
> > There is a device plugged into the port, which monitors its ethernet
> port. (The device is known to work otherwise)
> >
> > So, somehow I'm supposed to specify the topology of the connection.
> >
> > Any suggestions on how to go about debugging the connection? 
> Thanks.
> 
> Debugging how? I'd say the first thing is to use "ethtool em1" on the
> Linux box to see if it sees a link and what configuration it's using.
> On my machine, I still use "eth0", so:
> 
> [root at prophead ~]# ethtool eth0
> Settings for eth0:
> 	Supported ports: [ TP ]
> 	Supported link modes:   10baseT/Half 10baseT/Full
> 	                        100baseT/Half 100baseT/Full
> 	                        1000baseT/Half 1000baseT/Full
> 	Supported pause frame use: No
> 	Supports auto-negotiation: Yes
> 	Advertised link modes:  10baseT/Half 10baseT/Full
> 	                        100baseT/Half 100baseT/Full
> 	                        1000baseT/Half 1000baseT/Full
> 	Advertised pause frame use: Symmetric
> 	Advertised auto-negotiation: Yes
> 	Link partner advertised link modes:  10baseT/Half 10baseT/Full
> 	                                     100baseT/Half
> 100baseT/Full
> 	                                     1000baseT/Full
> 	Link partner advertised pause frame use: Symmetric
> 	Link partner advertised auto-negotiation: Yes
> 	Speed: 1000Mb/s
> 	Duplex: Full
> 	Port: Twisted Pair
> 	PHYAD: 1
> 	Transceiver: internal
> 	Auto-negotiation: on
> 	MDI-X: on
> 	Supports Wake-on: g
> 	Wake-on: g
> 	Current message level: 0x000000ff (255)
> 			       drv probe link timer ifdown ifup rx_err
> tx_err
> 	Link detected: yes
> 
> So you can see my NIC supports 10/100/1000baseT in both half and full
> duplex. The switch it's plugged into (the "Link partner") supports the
> same stuff and they both support auto negotiation. Between them
> they've
> negotiated a 1000baseT connection (1Gbps) in full duplex and eth0 has
> also determined that it is using twisted pair MDI-X (flipped) cabling
> (swapping the TX and RX pairs in the cable) and the very bottom shows
> eth0 has a link to the switch.
> 

OK. The output is mostly identical, with these exceptions:

    Advertised pause frame use: No
    Link partner ... missing
    PHYAD: 2
    MDI-X: on (auto)
    Supports Wake-on: pumbgCurrent message level: 0x00000007 (7)
			       drv probe link