1
Verify the likely cause
Allow required ICMPv6 traffic, verify the WAN MTU and configure MSS clamping only if the upstream link requires it.
FULL AI ANALYSIS
Devices receive IPv6 but some websites time out
Generated Sep 13, 2026, 11:55:04 AM
Analysis summary
The reported behaviour is consistent with path MTU discovery is blocked, causing larger IPv6 packets to disappear. The safest next step is to verify that hypothesis with a reversible test before making permanent configuration changes.
Possible causes
Path MTU discovery is blocked, causing larger IPv6 packets to disappear.
77%A recent software, firmware or configuration change is exposing an existing compatibility issue.
31%Suggested fixes
2
Validate and monitor
Reproduce the issue once after the change, review relevant logs or metrics, and keep a rollback path until the system has remained stable.