Added topology command-lines.
diff --git a/cli/src/main/java/org/onlab/onos/cli/net/TopologyCommand.java b/cli/src/main/java/org/onlab/onos/cli/net/TopologyCommand.java
new file mode 100644
index 0000000..a390025
--- /dev/null
+++ b/cli/src/main/java/org/onlab/onos/cli/net/TopologyCommand.java
@@ -0,0 +1,37 @@
+package org.onlab.onos.cli.net;
+
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cli.AbstractShellCommand;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyService;
+
+/**
+ * Lists summary of the current topology.
+ */
+@Command(scope = "onos", name = "topology",
+         description = "Lists summary of the current topology")
+public class TopologyCommand extends AbstractShellCommand {
+
+    private static final String FMT =
+            "time=%s, devices=%d, links=%d, clusters=%d, paths=%d";
+
+    protected TopologyService service;
+    protected Topology topology;
+
+    /**
+     * Initializes the context for all cluster commands.
+     */
+    protected void init() {
+        service = getService(TopologyService.class);
+        topology = service.currentTopology();
+    }
+
+    @Override
+    protected Object doExecute() throws Exception {
+        init();
+        print(FMT, topology.time(), topology.deviceCount(), topology.linkCount(),
+              topology.clusterCount(), topology.pathCount());
+        return null;
+    }
+
+}