The Intel 82578DM network interface card appears to be stuck at 100Mbps Full Duplex despite supporting Gigabit Ethernet (1000baseT). The router (Cisco RVS4000) is properly configured for Gigabit auto-negotiation, yet the link won't establish at the desired speed.

First, let's examine the card's capabilities and current status:

# Check supported and advertised modes
ethtool eth0 | grep -A5 "Supported link modes"
ethtool eth0 | grep -A5 "Advertised link modes"

# Check current driver settings
modinfo e1000e | grep -i version
dmesg | grep e1000e

Based on the provided information, several potential issues emerge:

• Cable quality issues (CAT5e or better required for Gigabit)
• Driver/firmware incompatibility (Linux e1000e driver v1.3.10-k2)
• Auto-negotiation problems between NIC and switch
• PCIe lane width limitations (shown as x1 in dmesg)

Method 1: Manual Speed Configuration

# Try setting speed manually (may cause link loss)
sudo ethtool -s eth0 speed 1000 duplex full autoneg off

# Alternative approach - advertise only Gigabit
sudo ethtool -s eth0 advertise 0x020

Method 2: Driver Parameter Tweaks

# Add to /etc/modprobe.d/e1000e.conf
options e1000e InterruptThrottleRate=3000,3000,3000
options e1000e SmartPowerDownEnable=0
options e1000e copybreak=256

If basic configuration doesn't work, try these deeper diagnostics:

# Check PCIe link width
lspci -vv -s $(ethtool -i eth0 | grep bus | cut -d' ' -f2) | grep LnkSta

# Monitor link negotiation
watch -n 1 ethtool eth0

# Check for packet errors
ethtool -S eth0 | grep -i error

The output shows firmware version 0.10-2, which might need updating:

# Check for firmware updates
sudo apt-get install linux-firmware
sudo update-initramfs -u

Since you have a second NIC (82574L), try swapping ports:

# Disable problematic NIC
sudo ifconfig eth0 down
sudo ip link set eth1 up

When dealing with stubborn Gigabit links, always verify both physical layer components (cables, connectors) and software configuration. The e1000e driver sometimes requires specific tuning parameters for optimal performance with certain Intel NIC revisions.

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When working with Intel 82578 network interfaces on Linux systems, you might encounter situations where the NIC stubbornly negotiates at 100Mbps despite being connected to a Gigabit-capable switch. The error manifests when attempting manual configuration:

# ethtool -s eth0 speed 1000
Cannot advertise speed 1000

This indicates the interface either cannot establish or maintain a 1000Mbps link, despite showing Gigabit capability in its specifications.

First, gather comprehensive interface information:

# Check current settings
ethtool eth0

# Show PCI device details
lspci -vvv -s 00:19.0

# View driver messages
dmesg | grep -i e1000e

# Check kernel module parameters
modinfo e1000e

From experience with similar cases, these factors typically contribute:

• Cable quality issues (Cat5e minimum required for Gigabit)
• Switch port misconfiguration despite auto-negotiation claims
• Driver/firmware incompatibilities
• Power management interference
• PCIe link width limitations

1. Verify Physical Layer

Test with a known-good Cat6 cable and different switch port. Check for errors:

ethtool -S eth0 | grep error

2. Driver Configuration

For Intel NICs, try these module parameters:

# Add to /etc/modprobe.d/e1000e.conf
options e1000e InterruptThrottleRate=3000,3000,3000
options e1000e SmartPowerDownEnable=0

Then reload the driver:

rmmod e1000e && modprobe e1000e

3. Manual Negotiation Attempt

Force the speed temporarily (may cause disconnection):

ethtool -s eth0 speed 1000 duplex full autoneg off

Monitor the outcome:

watch -n1 "ethtool eth0 | grep -E 'Speed|Link'"

4. Firmware Update

Check for updated NIC firmware:

ethtool -i eth0 | grep firmware

Download updates from Intel's website and flash using appropriate tools.

For persistent issues, enable debug logging:

echo 16 > /sys/module/e1000e/parameters/debug
dmesg -w

This reveals low-level link negotiation details that can pinpoint exactly where the handshake fails.

If all else fails, consider:

# Disable energy efficient Ethernet
ethtool --set-eee eth0 eee off

# Set specific advertised modes
ethtool -s eth0 advertise 0x020