I currently have a NAS (openmediavault based on debian) with a Realtek gigabit NIC (ASRock Q1900-ITX on-board LAN), but it won't advertise that it is gigabit-capable.
ethtool eth0 gives the following output:
Settings for eth0: Supported ports: [ TP MII ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Supported pause frame use: No Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Advertised pause frame use: Symmetric Receive-only Advertised auto-negotiation: Yes Link partner advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Link partner advertised pause frame use: Symmetric Receive-only Link partner advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full Port: MII PHYAD: 0 Transceiver: internal Auto-negotiation: on Supports Wake-on: pumbg Wake-on: g Current message level: 0x00000033 (51) drv probe ifdown ifup Link detected: yes
1000Mbit full duplex is supported by the driver and the board (as stated in hardware specs). The connected switch does advertise that mode, however the NIC does not.
Attempting to change the advertised mode with
ethtool -s eth0 advertise 0x020 or at least forcing the NIC into gigabit mode does not help. The command returns without any error message and the NIC goes down. After bringing it back up with
ifup eth0, speed and advertised modes are still set as they were before the change. The cable is cat6 and changing the cable does not solve the issue.
How can I get that network interface to advertise gigabit speed?