diff --git a/core/src/main/java/org/jruby/ext/socket/Ifaddr.java b/core/src/main/java/org/jruby/ext/socket/Ifaddr.java
index e411473e6da..3d6a077b046 100644
--- a/core/src/main/java/org/jruby/ext/socket/Ifaddr.java
+++ b/core/src/main/java/org/jruby/ext/socket/Ifaddr.java
@@ -15,6 +15,8 @@
 import java.net.SocketException;
 import java.net.UnknownHostException;
 
+import jnr.constants.platform.InterfaceInfo;
+
 /**
  *
  * @author Lucas Allan Amorim
@@ -32,6 +34,7 @@ public class Ifaddr extends RubyObject {
     private boolean isLink;
     private String netmask;
     private int index;
+    private int flags;
     private String flagStatus;
     private Addrinfo addr;
 
@@ -56,12 +59,14 @@ public Ifaddr(Ruby runtime, RubyClass metaClass, NetworkInterface ni, InterfaceA
         this.index = ni.getIndex();
         this.networkInterface = ni;
         this.isLink = false;
+        this.flags = 0;
         this.address = it.getAddress();
         this.broadcast = it.getBroadcast();
         this.interfaceAddress = it;
         setAddr(runtime);
         setNetmask(it);
         setInspectString(ni);
+        setInterfaceFlags(ni);
     }
 
     public Ifaddr(Ruby runtime, RubyClass metaClass, NetworkInterface ni) throws SocketException {
@@ -71,10 +76,12 @@ public Ifaddr(Ruby runtime, RubyClass metaClass, NetworkInterface ni) throws Soc
         this.isUp = ni.isUp();
         this.isPointToPoint = ni.isPointToPoint();
         this.index = ni.getIndex();
+        this.flags = 0;
         this.networkInterface = ni;
         this.isLink = true;
         setAddr(runtime);
         setInspectString(ni);
+        setInterfaceFlags(ni);
     }
 
     @JRubyMethod
@@ -111,10 +118,9 @@ public IRubyObject ifindex(ThreadContext context) {
         return context.runtime.newFixnum(index);
     }
 
-    @JRubyMethod(notImplemented = true)
+    @JRubyMethod
     public IRubyObject flags(ThreadContext context) {
-        // not implemented yet
-        return context.nil;
+        return context.runtime.newFixnum(flags);
     }
 
     @JRubyMethod
@@ -212,4 +218,19 @@ private String getBroadcastAsString() {
         return broadcast.toString().substring(1);
     }
 
+    private void setInterfaceFlags(NetworkInterface nif) throws SocketException {
+        if (isUp) {
+            flags |= InterfaceInfo.IFF_UP.value();
+        }
+        if (nif.supportsMulticast()) {
+            flags |= InterfaceInfo.IFF_MULTICAST.value();
+        }
+        if (isLoopback) {
+            flags |= InterfaceInfo.IFF_LOOPBACK.value();
+        }
+        if (isPointToPoint) {
+            flags |= InterfaceInfo.IFF_POINTOPOINT.value();
+        }
+    }
+
 }
diff --git a/core/src/main/java/org/jruby/ext/socket/RubySocket.java b/core/src/main/java/org/jruby/ext/socket/RubySocket.java
index eefa175d8b4..59f80b26cde 100644
--- a/core/src/main/java/org/jruby/ext/socket/RubySocket.java
+++ b/core/src/main/java/org/jruby/ext/socket/RubySocket.java
@@ -42,6 +42,7 @@
 import jnr.constants.platform.SocketMessage;
 import jnr.constants.platform.SocketOption;
 import jnr.constants.platform.TCP;
+import jnr.constants.platform.InterfaceInfo;
 import jnr.netdb.Protocol;
 import jnr.unixsocket.UnixSocketAddress;
 import jnr.unixsocket.UnixSocketChannel;
@@ -109,6 +110,8 @@ static void createSocket(Ruby runtime) {
         runtime.loadConstantSet(rb_mConstants, IPProto.class);
         runtime.loadConstantSet(rb_mConstants, Shutdown.class);
         runtime.loadConstantSet(rb_mConstants, TCP.class);
+        runtime.loadConstantSet(rb_mConstants, IP.class);
+        runtime.loadConstantSet(rb_mConstants, InterfaceInfo.class);
         runtime.loadConstantSet(rb_mConstants, NameInfo.class);
         runtime.loadConstantSet(rb_mConstants, SocketMessage.class);
 
@@ -133,14 +136,6 @@ static void createSocket(Ruby runtime) {
         rb_mConstants.setConstant("AI_DEFAULT", runtime.newFixnum(AddressInfo.AI_DEFAULT));
         rb_mConstants.setConstant("AI_MASK", runtime.newFixnum(AddressInfo.AI_MASK));
 
-        // More constants needed by specs
-        rb_mConstants.setConstant("IP_MULTICAST_TTL", runtime.newFixnum(IP.IP_MULTICAST_TTL.value()));
-        rb_mConstants.setConstant("IP_MULTICAST_LOOP", runtime.newFixnum(IP.IP_MULTICAST_LOOP.value()));
-        rb_mConstants.setConstant("IP_ADD_MEMBERSHIP", runtime.newFixnum(IP.IP_ADD_MEMBERSHIP.value()));
-        rb_mConstants.setConstant("IP_MAX_MEMBERSHIPS", runtime.newFixnum(IP.IP_MAX_MEMBERSHIPS.value()));
-        rb_mConstants.setConstant("IP_DEFAULT_MULTICAST_LOOP", runtime.newFixnum(IP.IP_DEFAULT_MULTICAST_LOOP));
-        rb_mConstants.setConstant("IP_DEFAULT_MULTICAST_TTL", runtime.newFixnum(IP.IP_DEFAULT_MULTICAST_TTL));
-
         rb_cSocket.includeModule(rb_mConstants);
 
         rb_cSocket.defineAnnotatedMethods(RubySocket.class);