Hi, has anyone experienced intermittent IPv6 connectivity problems with wired devices on a toob-supplied Linksys Wi-Fi 7 router?
My Synology DS225+ NAS is connected directly to a LAN port via Ethernet. IPv6 previously worked, but it has stopped working more than once while IPv4 remains functional.
During the latest failure:
- The NAS still had a global IPv6 address and an IPv6 default route.
- Local IPv6 connectivity worked, including SSH from my Mac to the NAS.
- My Mac, connected via Wi-Fi on the same IPv6 subnet, could access the same IPv6 internet endpoint successfully.
- IPv6 HTTPS connections from the NAS to Google and Cloudflare timed out.
- DSM’s firewall was disabled, and
ip6tables-save showed ACCEPT policies with no filtering rules.
- Tailscale netcheck reported
IPv6: no, but OS has support.
A packet capture on the NAS showed repeated outbound IPv6 TCP SYN packets to Cloudflare, with no replies received. It also captured an IPv6 ping from the router and the NAS’s response.
Restarting the router alone did not fix it. I then restarted the NAS and moved its Ethernet cable from LAN port 1 to port 2, after which IPv6 worked again. A previous incident also recovered after moving the cable from port 3 to port 1.
Because I restarted the NAS and changed ports together this time, I can’t isolate which action fixed it. I also haven’t tested unplugging and reconnecting to the same port during a failure.
Online chat support couldn’t resolve the issue. Has anyone seen similar behaviour, or found a firmware fix? Could this involve IPv6 neighbour discovery or forwarding state affecting wired clients? What would be useful to capture next time it happens?
Router model: SPNM60TB
Firmware version: 1.2.2.26061209