Skip to main content
This guide covers configuring, operating, and troubleshooting Ethernet connectivity on the Qualcomm Dragonwing IQ-8275 EVK. The platform supports interface enumeration, data path, link speed configuration, MAC address management, MTU configuration, and network diagnostics.

​
Prerequisites

  • IQ-8275 EVK hardware
  • Ethernet cable (RJ45)
  • Host PC on the same network as the IQ-8275 EVK
  • SSH client software
  • Basic Linux command-line knowledge

​
Architecture

ComponentDescription
Application Processor Subsystem (APSS)Runs on a Linux-based operating system
Ethernet driverLinux kernel driver providing data connectivity over a wired Ethernet interface
PHY driverLow-level driver managing the Ethernet physical layer; implements a state machine for PHY lifecycle from initialization to link establishment; interacts with MDIO to access PHY registers
Ethernet hardware1× QEP8081 PHY for 10/100/1000/2500 Mbps, enabled by RJ45 connector

​
Getting Started

​
Bring Up Ethernet

Establish access to the device via SSH over Wi-Fi or the serial prompt before proceeding. See the Set up the device section for instructions.
Flash the corresponding CDT on the device to ensure the correct configuration is used for Ethernet bring-up.
1

Configure MAC Address (optional)

The IQ-8275 EVK ships with a factory MAC address. Skip this step to use it as-is.To change the MAC address:
sudo ifconfig end0 hw ether XX:XX:XX:YY:YY:YY
This MAC address is valid only for the current boot cycle. After rebooting, the device reverts to the address from persistent storage.
2

Assign an IP Address

On a public network, the DHCP server assigns an IP address automatically. To assign a static IP address manually:
ifconfig end0 192.168.1.2
3

Configure MTU

ifconfig end0 down
ifconfig end0 mtu 1500
ifconfig end0 up
4

Verify Bring-Up

Confirm the following:
  • end0 is visible in ifconfig output
  • Interface status shows UP BROADCAST RUNNING MULTICAST
  • IP address is correctly assigned
  • MTU is set to the desired value (typically 1500)
  • No errors in RX/TX packet counters

​
Ethernet Operations

​
Check Connectivity

Use ping to verify connectivity between the device and a remote host. The client IP address must be in the same subnet as the device. 
ping 169.254.227.240

​
Configure NIC Settings

ethtool end0
ethtool -S end0

​
Configure Network Interface

ifconfig end0

​
Monitor Network Connections

netstat -r

​
Capture Network Traffic

sudo tcpdump -i any -s 0 -w /home/ubuntu/tcpdump.pcap

​
View Routing Table

ip r s

sudo ethtool -s end0 autoneg on speed 1000 duplex full

​
Troubleshooting

​
Collect Diagnostic Logs

1

Collect dmesg logs

sudo dmesg > /home/ubuntu/dmesg_logs.txt
2

Collect tcpdump logs

sudo tcpdump -i any -s 0 -w /home/ubuntu/tcpdump.pcap
Press Ctrl+C to stop capture.
3

Pull log files to host PC

scp ubuntu@<device_ip>:/home/ubuntu/tcpdump.pcap .
scp ubuntu@<device_ip>:/home/ubuntu/dmesg_logs.txt .
4

Collect diagnostic output

{
  echo "=== ETHTOOL OUTPUT ==="
  ethtool end0
  echo "=== ETHTOOL STATISTICS ==="
  ethtool -S end0
  echo "=== IFCONFIG OUTPUT ==="
  ifconfig end0
  echo "=== NETSTAT OUTPUT ==="
  netstat -r
  echo "=== IP ROUTE OUTPUT ==="
  ip route show
} > /home/ubuntu/ethernet_diagnostics.txt

​
Common Issues

ifconfig end0
ip route show
netstat -r
arp -a
sudo tcpdump -i end0 icmp
Solutions: Configure correct IP address and subnet mask; add default gateway if needed.
ethtool end0 | grep -E "Speed|Duplex"
ethtool -S end0 | grep -E "error|drop|collision"
ifconfig end0 | grep MTU
Solutions: Force 1000 Mbps full-duplex if auto-negotiation fails; replace cable if errors are detected.
ifconfig -a
sudo dmesg | grep -i ethernet
ls /sys/class/net/
Solutions: Ensure correct CDT is flashed; verify Ethernet driver is compiled in kernel; reboot and check again.
ifconfig end0 | grep ether
cat /var/persist/config.ini | grep MAC_ID
Solutions: Create or restore /var/persist/config.ini. Format: MDIOBUSID1: 1: MAC_ID01: XX:XX:XX:YY:YY:YY.

​
Command Reference

CommandPurposeExample
dmesgView kernel messagesdmesg | grep eth
ethtool <if>Check link statusethtool end0
ethtool -S <if>View NIC statisticsethtool -S end0
ifconfig <if>Check interface configifconfig end0
ip addr showShow IP addressesip addr show end0
ip route showShow routing tableip route show
ping <host>Test connectivityping 192.168.1.10
tcpdump -i <if>Capture packetstcpdump -i end0
netstat -rShow routesnetstat -r
arp -aShow ARP tablearp -a

​
Resources