networkd: add back path of MTU discovery for SIT

1 files changed, 8 insertions, 0 deletions

diff --git a/src/network/networkd-netdev-tunnel.c b/src/network/networkd-netdev-tunnel.c
index 174fe234fd..75876960b4 100644
--- a/src/network/networkd-netdev-tunnel.c
+++ b/src/network/networkd-netdev-tunnel.c
@@ -120,6 +120,14 @@ static int netdev_sit_fill_message_create(NetDev *netdev, Link *link, sd_rtnl_me
                 return r;
         }
 
+        r = sd_rtnl_message_append_u8(m, IFLA_IPTUN_PMTUDISC, t->pmtudisc);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_IPTUN_PMTUDISC attribute: %s",
+                                 strerror(-r));
+                return r;
+        }
+
         return r;
 }