Title: Jetson Orin Nano Super Developer Kit (L4T R39.2.0 / JetPack 7) Realtek RTL8168 intermittently negotiates 100 Mbps instead of 1 Gbps
Summary
The Ethernet interface on the official NVIDIA Jetson Orin Nano Super Developer Kit intermittently negotiates at 100 Mbps instead of 1 Gbps when connected to a Gigabit router/switch. The same Ethernet cable and the same switch port consistently negotiate at 1 Gbps when used with a laptop.
Disabling Energy Efficient Ethernet (EEE) with ethtool and rebooting appears to restore stable Gigabit operation.
Hardware
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Board: Official NVIDIA Jetson Orin Nano Super Developer Kit
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Ethernet controller: Realtek RTL8111/8168/8211/8411 PCIe Gigabit Ethernet Controller (PCI ID 10ec:8168, rev 15)
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Driver: r8168
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Wi-Fi: RTL8822CE (not related)
Software
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Jetson Linux (L4T): R39.2.0
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nvidia-l4t-core: 39.2.0-20260601141651
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Kernel variant: oot
/etc/nv_tegra_release
# R39 (release), REVISION: 2.0
# GCID: 45755727
# BOARD: generic
# DATE: Mon Jun 1 09:28:48 PM UTC 2026
Driver information
ethtool -i enP8p1s0
driver: r8168
version: 8.053.00-NAPI
bus-info: 0008:01:00.0
Problem description
After boot, the Ethernet interface frequently negotiates only 100 Mbps Full Duplex although:
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the connected router/switch supports Gigabit Ethernet,
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the Ethernet cable supports Gigabit,
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the same cable and the same switch port negotiate at 1 Gbps with a laptop.
Sometimes the Jetson negotiates at 1 Gbps, but after link renegotiation it falls back to 100 Mbps.
Kernel log also shows repeated link transitions:
r8168: enP8p1s0: link down
r8168: enP8p1s0: link up
This occurs multiple times during normal operation.
Evidence
When the issue occurs:
Speed: 100Mb/s
Duplex: Full
At one point the link partner advertised Gigabit:
Link partner advertised link modes:
1000baseT/Full
Later, after renegotiation, the link partner only advertised:
10baseT
100baseT
This causes the Jetson to negotiate only 100 Mbps.
Measured throughput using iperf3 during this state is approximately:
94-95 Mbit/s
which matches Fast Ethernet performance.
Workaround
Disabling EEE:
sudo ethtool --set-eee enP8p1s0 eee off
followed by a reboot results in:
Speed: 1000Mb/s
Duplex: Full
Measured throughput becomes:
iperf3
932-935 Mbit/s
which is the expected performance for Gigabit Ethernet.
Verification performed
The following components were verified:
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Same Ethernet cable tested with a laptop → negotiates 1 Gbps.
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Same router/switch port tested with a laptop → negotiates 1 Gbps.
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Jetson reports repeated Ethernet link down/up events.
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Realtek NIC hardware is capable of Gigabit operation after the workaround.
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No significant RX/TX error counters were observed.
Expected behavior
The Ethernet interface should reliably negotiate a 1 Gbps link with standard Gigabit Ethernet equipment without requiring EEE to be disabled or manual intervention after boot.
Actual behavior
The interface intermittently negotiates only 100 Mbps and repeatedly retrains the Ethernet link until EEE is disabled and the system is rebooted.
dmesg | grep -i r8168
[ 12.262077] r8168 0008:01:00.0: Adding to iommu group 33
[ 12.262290] r8168 Gigabit Ethernet driver 8.053.00-NAPI loaded
[ 12.262350] r8168 0008:01:00.0: enabling device (0000 → 0003)
[ 12.312313] r8168: This product is covered by one or more of the following patents: US6,570,884, US6,115,776, and US6,327,625.
[ 12.324357] r8168 Copyright (C) 2024 Realtek NIC software team nicfae@realtek.com
[ 12.410025] r8168 0008:01:00.0 enP8p1s0: renamed from eth0
[ 19.727728] r8168: enP8p1s0: link up
[ 660.476171] r8168 0008:01:00.0: invalid VPD tag 0x00 (size 0) at offset 0; assume missing optional EEPROM
ethtool -i enP8p1s0
driver: r8168
version: 8.053.00-NAPI
firmware-version:
expansion-rom-version:
bus-info: 0008:01:00.0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: yes
supports-priv-flags: no