While working with the Ethernet library on my Opta I stumbled upon this weird behavior. You can easily reproduce the issue with the following sketch: ```cpp #include <Ethernet.h> IPAddress ip(192, 168, 10, 15); IPAddress subnet(255, 255, 255, 0); IPAddress dns(1, 1, 1, 1); IPAddress gateway(192, 168, 10, 1); void setup() { Serial.begin(9600); Ethernet.begin(ip, dns, gateway, subnet); Serial.print("IP = "); Serial.print(Ethernet.localIP()); Serial.print(", DNS server = "); Serial.print(Ethernet.dnsServerIP()); Serial.print(", Default gateway = "); Serial.println(Ethernet.gatewayIP()); } void loop() { } ``` On the serial monitor I get the following output: ```text IP = 192.168.10.15, DNS server = 8.8.8.8, Default gateway = 192.168.10.1 ``` For some reason the DNS server always returns `8.8.8.8`. If I can provide further details let me know!