[CentOS] RTL8111/8168B always 100mbps

Tue Sep 27 05:20:35 UTC 2011
Emmanuel Noobadmin <centos.admin at gmail.com>

On 9/27/11, Muhammad Panji <sumodirjo at gmail.com> wrote:
> Dear All,
> I have an onboard Realtek RTL8111/8168B NIC. from lspci -vv :
>
> 02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd.
> RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 02)
>
> It is detected, but why the speed is always 100Mbps, already change
> cable but still no luck. I use ethtool and from the output it seems
> that system know that this NIC support gigabit speed :

What network switch is this connected to? Does it work if you disable
auto-negotiation and force the link speed to 1Gbps?