diff --git a/ripngd/ripngd.c b/ripngd/ripngd.c index 2a32b934f2..96206e2b08 100644 --- a/ripngd/ripngd.c +++ b/ripngd/ripngd.c @@ -829,8 +829,10 @@ ripng_route_process (struct rte *rte, struct sockaddr_in6 *from, * with the new one in below. */ break; - /* Metrics are same. Keep "rinfo" null and the new route - * is added in the ECMP list in below. */ + /* Metrics are same. Unless ECMP is disabled, keep "rinfo" null and + * the new route is added in the ECMP list in below. */ + if (! ripng->ecmp) + break; } } @@ -874,11 +876,24 @@ ripng_route_process (struct rte *rte, struct sockaddr_in6 *from, same = (IN6_ARE_ADDR_EQUAL (&rinfo->from, &from->sin6_addr) && (rinfo->ifindex == ifp->ifindex)); + /* + * RFC 2080 - Section 2.4.2: + * "If the new metric is the same as the old one, examine the timeout + * for the existing route. If it is at least halfway to the expiration + * point, switch to the new route. This heuristic is optional, but + * highly recommended". + */ + if (!ripng->ecmp && !same && + rinfo->metric == rte->metric && rinfo->t_timeout && + (thread_timer_remain_second (rinfo->t_timeout) < (ripng->timeout_time / 2))) + { + ripng_ecmp_replace (&newinfo); + } /* Next, compare the metrics. If the datagram is from the same router as the existing route, and the new metric is different than the old one; or, if the new metric is lower than the old one; do the following actions: */ - if ((same && rinfo->metric != rte->metric) || + else if ((same && rinfo->metric != rte->metric) || rte->metric < rinfo->metric) { if (listcount (list) == 1)