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 : Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full have change the driver r8169 with r8168 and follow the guide on CentOS wiki http://wiki.centos.org/AdditionalResources/HardwareList/RealTekRTL8111b but still it only get 100Mbps speed. I user kernel 2.6.18-274.3.1.el5 and 2.6.18-274.3.1.el5-PAE. on another machine with the same specs I use kernel 2.6.18-238.9.1.el5 and the gigabit speed works. Any idea why this happened and how to solve it? Thank you. Regards, -- ----- Muhammad Panji http://www.panji.web.id http://www.kurungsiku.com http://sumodirjo.wordpress.com http://www.kurungsiku.web.id http://www.linuxbox.web.id