[Network][Route] How to ping Destination machine successfully

 Source                  Router                  Destination
 111.2.1.100             111.2.1.250             222.7.1.200

+----------+            +----------+            +----------+
|          |            |          |            |          |
|          +------------+          +------------+          |
+----------+            +----------+            +----------+

    ip route add 222.7.1.200     via   111.2.1.250          
    ping  222.7.1.200 success