diff --git a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/InterfaceService.java b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/InterfaceService.java
new file mode 100644
index 0000000..f9e881f
--- /dev/null
+++ b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/InterfaceService.java
@@ -0,0 +1,37 @@
+package org.onlab.onos.sdnip;
+
+import java.util.Set;
+
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.sdnip.config.Interface;
+import org.onlab.packet.IpAddress;
+
+/**
+ * Provides information about the interfaces in the network.
+ */
+public interface InterfaceService {
+    /**
+     * Retrieves the entire set of interfaces in the network.
+     *
+     * @return the set of interfaces
+     */
+    Set<Interface> getInterfaces();
+
+    /**
+     * Retrieves the interface associated with the given connect point.
+     *
+     * @param connectPoint the connect point to retrieve interface information
+     * for
+     * @return the interface
+     */
+    Interface getInterface(ConnectPoint connectPoint);
+
+    /**
+     * Retrieves the interface that matches the given IP address. Matching
+     * means that the IP address is in one of the interface's assigned subnets.
+     *
+     * @param ipAddress IP address to match
+     * @return the matching interface
+     */
+    Interface getMatchingInterface(IpAddress ipAddress);
+}