@@ -340,7 +340,18 @@ STP BPDUs.
.BR "guard on " or " guard off "
Controls whether STP BPDUs will be processed by the bridge port. By default,
the flag is turned off allowed BPDU processing. Turning this flag on will
-cause the port to stop processing STP BPDUs.
+disables
+the bridge port if a STP BPDU packet is received.
+
+If running Spanning Tree on bridge, hostile devices on the network
+may send BPDU on a port and cause network failure. Setting
+.B guard on
+will detect and stop this by disabling the port.
+The port will be restarted if link is brought down, or
+removed and reattached. For example if guard is enable on
+eth0:
+
+.B ip link set dev eth0 down; ip link set dev eth0 up
.TP
.BR "hairpin on " or " hairpin off "
Document that guard disable the port and how to reenable it Signed-off-by: Bastien Roucariès <rouca@debian.org> --- man/man8/bridge.8 | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)