SDK • IPv6 routing with Pico2W

C/C++ SDK version 2.2.0

I'm experimenting with IPv6 support in the LWIP stack on a Pico 2W. I can see link-local and global IPv6 addresses allocated on the Pico and I can contact other hosts on the local network using IPv6. But my test code does not connect to external IPv6 hosts. Other systems on the local network can connect to the IPv6 host correctly and the Pico can connect to external hosts using IPv4.

Are there any known issues with router discovery in LWIP? I have these defined in lwipopts.h:

#define LWIP_IPV6 1
#define LWIP_IPV6_DHCP6 1
#define LWIP_IPV6_AUTOCONFIG 1
#define LWIP_IPV6_SCOPES 1
#define LWIP_IPV6_SCOPES_DEBUG 1
#define LWIP_IPV6_DUP_DETECT_ATTEMPTS 0

Statistics: Posted by rde1 — Mon Feb 16, 2026 11:28 am

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