gnrc_ipv6_nib: Neighbor Solicitation ping-pong #18164
Description
Description
When debugging rapidly declining network performance, I noticed something weird: Two nodes would ping-pong neighbor solicitations to each other on the DOSE bus, life-locking the system:
Steps to reproduce the issue
To be determined…
Expected results
Nodes should answer to a neighbor solicitation with a neighbor advertisement, not another neighbor solicitation.
Actual results
This was predated by one node seemingly ignoring the NAs before, it would keep re-sending NS:
NS-weirdness.pcapng.gz
2022-06-02 18:28:01,432 - INFO # > nib neigh
2022-06-02 18:28:01,432 - INFO #
2022-06-02 18:28:01,434 - INFO # fe80::18cf:efff:fe0d:9a97 dev #4 lladdr 1A:CF:EF:0D:9A:97 STALE
2022-06-02 18:28:01,435 - INFO # fe80::acde:b5ff:fe69:1703 dev #4 lladdr AE:DE:B5:69:17:03 router UNREACHABLE
2022-06-02 18:30:35,842 - INFO # > nib route
2022-06-02 18:30:35,842 - INFO #
2022-06-02 18:30:35,843 - INFO # fd11:e000::/19 dev #4
2022-06-02 18:30:35,844 - INFO # default via fe80::acde:b5ff:fe69:1703 dev #4
2022-06-02 18:30:44,002 - INFO # > nib prefix
2022-06-02 18:30:44,002 - INFO #
2022-06-02 18:30:44,004 - INFO # fd11:e000::/19 dev #4
2022-06-02 18:30:53,611 - INFO # > ifconfig
2022-06-02 18:30:53,612 - INFO #
2022-06-02 18:30:53,657 - INFO # Iface 4 HWaddr: 66:F6:D6:18:12:9A
2022-06-02 18:30:53,658 - INFO # L2-PDU:1500 MTU:1500 HL:64 Source address length: 6
2022-06-02 18:30:53,658 - INFO # Link type: wired
2022-06-02 18:30:53,660 - INFO # inet6 addr: fe80::64f6:d6ff:fe18:129a scope: link VAL
2022-06-02 18:30:53,661 - INFO # inet6 addr: fd11:e000::64f6:d6ff:fe18:129a scope: global VAL
2022-06-02 18:30:53,662 - INFO # inet6 group: ff02::1
2022-06-02 18:30:53,663 - INFO # inet6 group: ff02::1:ff18:129a
Versions
RIOT b94dd60