• Jiri Benc's avatar
    ipv6: router reachability probing · 7e980569
    Jiri Benc authored
    RFC 4191 states in 3.5:
    
       When a host avoids using any non-reachable router X and instead sends
       a data packet to another router Y, and the host would have used
       router X if router X were reachable, then the host SHOULD probe each
       such router X's reachability by sending a single Neighbor
       Solicitation to that router's address.  A host MUST NOT probe a
       router's reachability in the absence of useful traffic that the host
       would have sent to the router if it were reachable.  In any case,
       these probes MUST be rate-limited to no more than one per minute per
       router.
    
    Currently, when the neighbour corresponding to a router falls into
    NUD_FAILED, it's never considered again. Introduce a new rt6_nud_state
    value, RT6_NUD_FAIL_PROBE, which suggests the route should not be used but
    should be probed with a single NS. The probe is ratelimited by the existing
    code. To better distinguish meanings of the failure values, rename
    RT6_NUD_FAIL_SOFT to RT6_NUD_FAIL_DO_RR.
    Signed-off-by: default avatarJiri Benc <jbenc@redhat.com>
    Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    7e980569
route.c 76.9 KB