03 Ethernet

1 Ethernet Interface Overview

GM-3568JHF development board is equipped with 2 Gigabit Ethernet interfaces, implemented based on the integrated Ethernet controller of RK3568J processor, supporting high-speed network communication and multi-network environment applications.

Interface	Type	Device Name	Interface Standard	Max Rate	Description
ETH0	RGMII	end0	IEEE 802.3	1000Mbps	Primary Ethernet interface, default network card
ETH1	RGMII	end1	IEEE 802.3	1000Mbps	Secondary Ethernet interface

2 Network Connectivity Test

ETH0 RGMII: end0, default network card, usually used for primary network connection
ETH1 RGMII: end1, secondary network card, can be used for network redundancy or isolation
Connection Method: Use an Ethernet cable to connect the corresponding network port of the development board and the PC to the same router or switch.

Enter the file system and execute the following command to get the IP and view the network port configuration information.

root@linaro-alip:/# ifconfig
end0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.49.176  netmask 255.255.255.0  broadcast 192.168.49.255
        inet6 fe80::561a:9e84:b5bd:20d7  prefixlen 64  scopeid 0x20<link>
        ether 32:b0:e6:11:eb:7e  txqueuelen 1000  (Ethernet)
        RX packets 3236  bytes 236287 (230.7 KiB)
        RX errors 0  dropped 569  overruns 0  frame 0
        TX packets 745  bytes 63449 (61.9 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 69

end1: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 36:b0:e6:11:eb:7e  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 67

Execute the following command to test whether the network port connection to the external network is normal, taking visiting "www.baidu.com" as an example. "-I" specifies the network port, if "-I" is not added, the default network card is used. You can press "Ctrl + C" to terminate the ping command.

root@linaro-alip:/# ping www.baidu.com -I end0
PING www.a.shifen.com (183.2.172.42) 56(84) bytes of data.
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=1 ttl=50 time=9.28 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=2 ttl=50 time=8.77 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=3 ttl=50 time=8.65 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=4 ttl=50 time=8.83 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=5 ttl=50 time=8.63 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=6 ttl=50 time=8.73 ms

--- www.a.shifen.com ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 5007ms
rtt min/avg/max/mdev = 8.630/8.813/9.275/0.216 ms

root@linaro-alip:/# ping www.baidu.com -I end1
PING www.a.shifen.com (183.2.172.42) 56(84) bytes of data.
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=1 ttl=50 time=8.35 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=2 ttl=50 time=8.88 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=3 ttl=50 time=9.07 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=4 ttl=50 time=8.91 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=5 ttl=50 time=8.67 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=6 ttl=50 time=8.66 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=7 ttl=50 time=8.78 ms
64 bytes from 183.2.172.42 (183.2.172.42): icmp_seq=8 ttl=50 time=8.41 ms

--- www.a.shifen.com ping statistics ---
8 packets transmitted, 8 received, 0% packet loss, time 7011ms
rtt min/avg/max/mdev = 8.352/8.716/9.068/0.230 ms

3 TCP Bandwidth Test

1) Server Side

Connect the development board to the Internet and install the iperf3 tool, executing the following commands:

root@linaro-alip:/# sudo apt update
root@linaro-alip:/# sudo apt install iperf3

The development board acts as the server, executing the following command:

root@linaro-alip:/# iperf3 -s
-----------------------------------------------------------
Server listening on 5201 (test #1)
-----------------------------------------------------------

2) Client Side

The iperf3 tool for Windows can be obtained from the test toolkit.

Open PowerShell in Windows, enter the path where the iperf3 tool is located, and use Windows as the client to send data by executing the following command:

.\iperf3.exe -c 192.168.137.149 // 192.168.137.149 is the server IP address

3) Test Results

Server Side

root@linaro-alip:/# iperf3 -s
-----------------------------------------------------------
Server listening on 5201 (test #1)
-----------------------------------------------------------
Accepted connection from 192.168.49.85, port 53618
[  5] local 192.168.49.245 port 5201 connected to 192.168.49.85 port 53619
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec   112 MBytes   936 Mbits/sec
[  5]   1.00-2.00   sec   112 MBytes   937 Mbits/sec
[  5]   2.00-3.00   sec   112 MBytes   939 Mbits/sec
[  5]   3.00-4.00   sec   112 MBytes   938 Mbits/sec
[  5]   4.00-5.00   sec   112 MBytes   937 Mbits/sec
[  5]   5.00-6.00   sec   111 MBytes   931 Mbits/sec
[  5]   6.00-7.00   sec   111 MBytes   929 Mbits/sec
[  5]   7.00-8.00   sec   111 MBytes   930 Mbits/sec
[  5]   8.00-9.00   sec   111 MBytes   933 Mbits/sec
[  5]   9.00-10.00  sec   111 MBytes   929 Mbits/sec
[  5]  10.00-10.00  sec   265 KBytes   885 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.00  sec  1.09 GBytes   934 Mbits/sec                  receiver
-----------------------------------------------------------

Client Side

ETH

4 Advanced Network Configuration

4.1 Static IP Configuration

1) Temporary Configuration (Lost after Reboot)

# Configure ETH0 static IP
sudo ifconfig end0 192.168.1.100 netmask 255.255.255.0 up

# Add default gateway
sudo route add default gw 192.168.1.1 end0

# Configure DNS
echo "nameserver 8.8.8.8" | sudo tee /etc/resolv.conf

2) Permanent Configuration

Edit network configuration file:

# Edit network interface configuration
sudo nano /etc/network/interfaces

# Add the following content
auto end0
iface end0 inet static
    address 192.168.1.100
    netmask 255.255.255.0
    gateway 192.168.1.1
    dns-nameservers 8.8.8.8 8.8.4.4

auto end1
iface end1 inet static
    address 192.168.2.100
    netmask 255.255.255.0

4.2 Network Bridge Configuration

Create a network bridge to bridge two network ports:

# Install bridge tool
sudo apt-get install bridge-utils

# Create bridge
sudo brctl addbr br0

# Add network ports to bridge
sudo brctl addif br0 end0
sudo brctl addif br0 end1

# Enable bridge
sudo ifconfig br0 up

# Configure bridge IP
sudo ifconfig br0 192.168.1.100 netmask 255.255.255.0

4.3 VLAN Configuration

Configure VLAN for network isolation:

# Install VLAN tool
sudo apt-get install vlan

# Load 8021q module
sudo modprobe 8021q

# Create VLAN interfaces
sudo vconfig add end0 100
sudo vconfig add end0 200

# Configure VLAN interface IP
sudo ifconfig end0.100 192.168.100.1 netmask 255.255.255.0 up
sudo ifconfig end0.200 192.168.200.1 netmask 255.255.255.0 up

5 Network Monitoring and Diagnosis

5.1 Network Status Monitoring

# View network interface statistics
cat /proc/net/dev

# View network connection status
netstat -tuln

# View routing table
route -n

# View ARP table
arp -a

# Real-time monitoring of network traffic
sudo iftop -i end0

5.2 Network Performance Test

1) Bandwidth Test

# Server side (Development board)
iperf3 -s -p 5201

# Client side (PC)
iperf3 -c 192.168.1.100 -p 5201 -t 30 -i 1

# UDP Test
iperf3 -c 192.168.1.100 -u -b 1000M -t 10

2) Latency Test

# Ping test
ping -c 100 -i 0.01 192.168.1.1

# High-precision test using hping3
sudo hping3 -c 1000 -i u100 192.168.1.1

5.3 Network Packet Capture Analysis

# Install tcpdump
sudo apt-get install tcpdump

# Capture packets on specified interface
sudo tcpdump -i end0 -w capture.pcap

# View packets in real-time
sudo tcpdump -i end0 -n

# Filter specific protocols
sudo tcpdump -i end0 tcp port 80

6 Troubleshooting

1) Network Port Connection Failure

Check Steps:

# Check interface status
sudo ethtool end0

# Check cable connection
sudo ethtool end0 | grep "Link detected"

# Check driver loading
lsmod | grep stmmac

# Restart network service
sudo systemctl restart networking

2) Slow Network Speed

Possible Causes and Solutions:

# Check negotiation speed
sudo ethtool end0 | grep Speed

# Force Gigabit speed
sudo ethtool -s end0 speed 1000 duplex full autoneg off

# Check network congestion
sudo netstat -i

# Optimize network parameters
echo 1 > /proc/sys/net/ipv4/tcp_window_scaling

3) Packet Loss

Diagnosis and Solution:

# View packet loss statistics
cat /proc/net/dev | grep end0

# Check network backlog
cat /proc/sys/net/core/netdev_max_backlog

# Increase backlog size
echo 5000 > /proc/sys/net/core/netdev_max_backlog

4) IP Conflict

Solution:

# Check IP conflict
sudo arping -D -I end0 192.168.1.100

# Release and renew IP
sudo dhclient -r end0
sudo dhclient end0