From 7d26945ad8b587872d6d4a87e63e91cded58da5d Mon Sep 17 00:00:00 2001
From: Christian Franke <chris@opensourcerouting.org>
Date: Tue, 20 Nov 2018 19:18:42 +0100
Subject: [PATCH] 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
---
 isisd/isis_mt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/isisd/isis_mt.c b/isisd/isis_mt.c
index 7493b90d33..f7d4c7170f 100644
--- 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 {
-- 
2.39.5