networkd: turn on LLDP reception by default, in "routers-only" mode

This way "networkctl status" becomes a bit more useful by default, as router
information is just visible, without any further configuration.

LLDP reception is fully passive and relatively low simple and low traffic,
hence this should be safe to enable by default.

2 files changed, 3 insertions, 1 deletions

diff --git a/man/systemd.network.xml b/man/systemd.network.xml
index 2de2a550db..bbdcace563 100644
--- a/man/systemd.network.xml
+++ b/man/systemd.network.xml
@@ -339,7 +339,7 @@
             <literal>routers-only</literal>. When true, incoming LLDP packets are accepted and a database of all LLDP
             neighbors maintained. If <literal>routers-only</literal> is set only LLDP data of various types of routers
             is collected and LLDP data about other types of devices ignored (such as stations, telephones and
-            others). If false, LLDP reception is disabled. Defaults to <literal>false</literal>. Use
+            others). If false, LLDP reception is disabled. Defaults to <literal>routers-only</literal>. Use
             <citerefentry><refentrytitle>networkctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> to query the
             collected neighbor data.
             </para>
diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index a6512d26e5..935042260b 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -119,6 +119,8 @@ static int network_load_one(Manager *manager, const char *filename) {
         network->allow_port_to_be_root = true;
         network->unicast_flood = true;
 
+        network->lldp_mode = LLDP_MODE_ROUTERS_ONLY;
+
         network->llmnr = RESOLVE_SUPPORT_YES;
         network->mdns = RESOLVE_SUPPORT_NO;
         network->dnssec_mode = _DNSSEC_MODE_INVALID;