--- rdma-core-22.1.orig/redhat/rdma.ifup-ib	2019-08-27 10:15:27.537044097 -0400

+++ rdma-core-22.1/redhat/rdma.ifup-ib	2019-08-27 10:14:42.453131658 -0400

@@ -110,19 +110,25 @@ if [ -e /sys/class/net/${DEVICE}/mode ];

     # cycle, allowing people to change the mode without rebooting

     if [ "${CONNECTED_MODE}" = yes ]; then

         echo connected > /sys/class/net/${DEVICE}/mode

-	# cap the MTU where we should based upon mode

+	# set default MTU based upon mode if none specified

 	[ -z "$MTU" ] && MTU=65520

-	[ "$MTU" -gt 65520 ] && MTU=65520

     else

         echo datagram > /sys/class/net/${DEVICE}/mode

-	# cap the MTU where we should based upon mode

+	# set default MTU based upon mode if none specified

 	[ -z "$MTU" ] && MTU=2044

-	[ "$MTU" -gt 4092 ] && MTU=4092

+    fi

+    # cap the MTU to roughly the same as Ethernet's max MTU

+    if [ "$MTU" -gt 65520 ]; then

+        MTU=65520

+        net_log $"Warning: capping device ${DEVICE} MTU to ${MTU}."

     fi

 fi

 if [ -n "${MTU}" ]; then

     ip link set dev ${DEVICE} mtu ${MTU}

+    if [ "$?" ]; then

+        net_log $"Error setting device ${DEVICE} MTU to ${MTU}, using HW default."

+    fi

 fi

 # slave device?