From a7acce6db38bbedbb331029d2066f6181ee96d91 Mon Sep 17 00:00:00 2001 From: Donald Sharp Date: Tue, 19 May 2015 17:24:44 -0700 Subject: [PATCH] Section 16.0 of rfc2328 (OSPF) specifies that the short-path calculation to a node should be constructed with the sum of all path costs (metrics) to the node (pretty simple huh). There is a usage of metric typified by the "max-metric router-lsa" command in many networking stacks that allows a router to gracefully "remove" itself from a topology by advertising the maximum value of metric in it's router LSAs (16 bits of "1"). In this case, the router will continue to forward any traffic sent to it while these "max-metric" LSAs are propagated through the network; at which point, the router can be taken out of service. The correct handling of this in ospfd would use this metric as part of the calculation, disuading other routers from using it for transit traffic (assuming a better path exits). Unfortunately, the ospfd behavior is to remove these links from the SPF calculation. This patch changes the behavior to omit this exception handling. Signed-off-by: JR Rivers --- ospfd/ospf_spf.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/ospfd/ospf_spf.c b/ospfd/ospf_spf.c index a7155bc64a..0148316296 100644 --- a/ospfd/ospf_spf.c +++ b/ospfd/ospf_spf.c @@ -838,13 +838,6 @@ ospf_spf_next (struct vertex *v, struct ospf_area *area, if ((type = l->m[0].type) == LSA_LINK_TYPE_STUB) continue; - /* Infinite distance links shouldn't be followed, except - * for local links (a stub-routed router still wants to - * calculate tree, so must follow its own links). - */ - if ((v != area->spf) && l->m[0].metric >= OSPF_OUTPUT_COST_INFINITE) - continue; - /* (b) Otherwise, W is a transit vertex (router or transit network). Look up the vertex W's LSA (router-LSA or network-LSA) in Area A's link state database. */ -- 2.39.5