[CentOS] gigE -> 100Mb problems

Tue Oct 11 04:31:53 UTC 2016
John R Pierce <pierce at hogranch.com>

On 10/10/2016 5:33 PM, John R Pierce wrote:
> I've got a pair of identical CentOS 6.7 servers, with SuperMicro 
> X8DTE-F motherboards, these have 2 each Intel  82574L ethernet ports.  
> The eth0 ports are plugged in with 10' runs of brand new cat 5e cable 
> to a Cisco Nexxus 9000 switch (provided by the data center).
>
> These servers keep coming up at 100baseT rather than gigE. I've 
> swapped ports and cables with a different server, that server gets 
> gigE but these supermicro's are stuck at 100baseT regardless of the 
> port or cableused.
>
> 'ethtool eth0'  says its gigE, but 'mii-tool -v eth0' says its 
> 100baseT and doesn't even list gigE as an option, and the cisco 
> switches see it as 100baseT too.
>
> anyone else run into anything like this before?

oh.

# mii-tool -v eth0
eth0: negotiated, link ok
   product info: vendor 00:50:43, model 11 rev 1
   basic mode:   autonegotiation enabled
   basic status: autonegotiation complete, link ok
   capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD
   advertising:  100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD 
flow-control

# ethtool eth0
Settings for eth0:
         Supported ports: [ TP ]
         Supported link modes:   10baseT/Half 10baseT/Full
                                 100baseT/Half 100baseT/Full
                                 1000baseT/Full
         Supported pause frame use: No
         Supports auto-negotiation: Yes
         Advertised link modes:  10baseT/Half 10baseT/Full
                                 100baseT/Half 100baseT/Full
                                 1000baseT/Full
         Advertised pause frame use: No
         Advertised auto-negotiation: Yes
         Speed: 1000Mb/s
         Duplex: Full
         Port: Twisted Pair
         PHYAD: 1
         Transceiver: internal
         Auto-negotiation: on
         MDI-X: on (auto)
         Supports Wake-on: pumbg
         Wake-on: g
         Current message level: 0x00000007 (7)
                                drv probe link
         Link detected: yes

-- 
john r pierce, recycling bits in santa cruz