isisd: Consider non-mt links usable when either v4 or v6 works

When we run in non-mt mode, we should consider links which have either
working IPv4 or IPv6 active and look at the neighbors nlpids to judge
wether a link is usable.

Fixes: #3336

diff --git a/isisd/isis_mt.c b/isisd/isis_mt.c
index 7493b90d33638a63e8c812c86db1a2c3aa6031f2..f7d4c7170f5c8a759a011e50e4d86d58c3ac5852 100644 (file)
--- a/isisd/isis_mt.c
+++ b/isisd/isis_mt.c
@@ -398,7 +398,7 @@ bool tlvs_to_adj_mt_set(struct isis_tlvs *tlvs, bool v4_usable, bool v6_usable,
                    && !tlvs->mt_router_info_empty) {
                        /* Other end does not have MT enabled */
                        if (mt_settings[i]->mtid == ISIS_MT_IPV4_UNICAST
-                           && v4_usable)
+                           && (v4_usable || v6_usable))
                                adj_mt_set(adj, intersect_count++,
                                           ISIS_MT_IPV4_UNICAST);
                } else {