Description

This article explains why the "/kernel: nd6_cache_lladdr: no route to src fe80::ad19:d69b:851e:32f9 dst=ff02::0002 received on ifl" log message is generated.

Symptoms

The default IPv6 link local address starts in the FE80 range. If this default value on the router is changed to another address (for example, FE81), the router will start generating the following error message:

"/kernel: nd6_cache_lladdr: no route to src fe80::ad19:d69b:851e:32f9 dst=ff02::0002 received on ifl"

Solution

These log messages appear only when there is another IPv6 host connected to the other end of the interface on the router, as explained in the scenario below:

  • A PC with IPv6 addressing enabled is connected to a router.

  • The PC has a default link local address starting with FE80.

  • On the router, the default link local address is changed to fe81::ad19:d69b:851e:32f9.

  • When the PC comes online, it starts sending a Router Solicitation (RS) message with a source link-local address in the FE80::/64 range.

  • Upon receipt of this RS from an unknown source link-local address, the router generates this log message:

    • "/kernel: nd6_cache_lladdr: no route to src fe80::ad19:d69b:851e:32f9 dst=ff02::0002 received on ifl"

  • This is the normal response when the address starting with FE80 is unknown to the router.

These messages are cosmetic. They do not impact service.

To prevent these messages from being reported, enter the command below on the device:

set protocols neighbor-discovery onlink-subnet-only

Modification History

19-11-2025: Minor, non-technical edit