In your letter dated Wed, 4 Mar 2020 21:10:09 +0100 you wrote: >This flag was introduced in a 2008 Security Advisory, because "non-neighbors" >could abuse Neighbor Discovery to potentially cause denial-of-service situatio >ns. >In my situation it caused valid Neighbor Solicitation packets from my provider > to be silently dropped, making the connection effectively unusable.
In theory, the onlink status of a prefix should be announced in in router advertisements and should be consistent across all nodes on a subnet. In that sense, if this check fails then the network is misconfigured. (In the real world we can assume that many networks are misconfigured). That said, there is a specific check in processing Neighbor Discovery packets that the hop limit is equal to 255. In that sense any node that manages to send a packet with hop limit 255 is a neighbor, so I don't quite see how there could be an attack by non-neighbors. _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
