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I have a server in a data center, which has an Ethernet NIC card with Fibre support. I have a 1Gbps connection and my ISP asked me to make sure the settings on my device are as follows:

Full Duplex, 1000meg and NO Auto Negotiation

However, I just realized that my NIC only supports 10000T. Here is the output from ethtool eth2

Settings for eth2:
    Supported ports: [ FIBRE ]
    Supported link modes:   10000baseT/Full 
    Supports auto-negotiation: No
    Advertised link modes:  10000baseT/Full 
    Advertised pause frame use: No
    Advertised auto-negotiation: No
    Speed: Unknown!
    Duplex: Unknown! (255)
    Port: FIBRE
    PHYAD: 0
    Transceiver: external
    Auto-negotiation: off
    Supports Wake-on: d
    Wake-on: d
    Current message level: 0x00000014 (20)
                   link ifdown
    Link detected: no

I haven't yet connected the cable to the NIC. Do you think there will be a "speed mismatch", as the ISP end is configured at 1000T and my NIC supports only 10000T?

PS: the make/model of NIC is: Mellanox ConnectX-3 En.

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What's the EXACT make and model of NIC? – Chopper3 Jun 18 '12 at 16:09
Mellanox ConnectX-3 En. – Tarandeep Gill Jun 18 '12 at 16:11
up vote 4 down vote accepted

Yes - this card appears to only support 10G. It is possible that if the card also has an SFP+ slot that it might support 1000baseSX fiber (or similar) but without knowing more about the model of NIC, etc it is hard to say.

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Yes, the card comes with an SFP+ slot. I have the following transreceiver installed: Mellanox MFM1T02A-SR Module – Tarandeep Gill Jun 18 '12 at 16:15
Yep, 100% 10Gbps only sorry, get another 1Gbs NIC. – Chopper3 Jun 18 '12 at 16:17
Looking at the specs for the card it appears to be 10G only, so you are likely out of luck unless you use a different NIC. – rnxrx Jun 18 '12 at 16:18

That's a 10Gbps & 40Gbps ONLY NIC - it can't run at any other speed.

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