$ lspci -nnkd 10ec:8168
05:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller [10ec:8168] (rev 03)
Kernel driver in use: r8169
Kernel modules: r8169
Added by rsandu, August 25th, 2011
This card (same VendorID, rev. 01, integrated on a Giga-byte Technology GA-EP45-DS5 Motherboard [1458:e000]) works very badly when coupled in the same system with a separate D-Link System Inc DGE-528T Gigabit Ethernet Adapter [1186:4300] (rev 10).
On CentOS 6.0 I've experienced frequent disconnections, randomly, with no apparent cause. Both cards appear to use the r8169 kernel module. Cannot test this in depth on Trisquel 4.5.1 Slaine (both cards works normally, at first sight, but on CentOS6 disconnections occured after some time).