diff --git a/include/net/if.h b/include/net/if.h
index 7c93ec1635..9944f9eb89 100644
--- a/include/net/if.h
+++ b/include/net/if.h
@@ -54,8 +54,10 @@
 #define IFF_POINTOPOINT    (1 << 6)  /* Is point-to-point link */
 #define IFF_NOARP          (1 << 7)  /* ARP is not required for this packet */
 #define IFF_NAT            (1 << 8)  /* NAT is enabled for this interface */
+#define IFF_SLAVE          (1 << 11) /* Slave of a load balancer. */
 #define IFF_MULTICAST      (1 << 12) /* Supports multicast. */
 #define IFF_BROADCAST      (1 << 13) /* Broadcast address valid. */
+#define IFF_DYNAMIC        (1 << 15) /* Dialup device with changing addresses. */
 
 /* Interface flag helpers */
 
@@ -67,6 +69,8 @@
 #define IFF_SET_POINTOPOINT(f) do { (f) |= IFF_POINTOPOINT; } while (0)
 #define IFF_SET_MULTICAST(f)   do { (f) |= IFF_MULTICAST; } while (0)
 #define IFF_SET_BROADCAST(f)   do { (f) |= IFF_BROADCAST; } while (0)
+#define IFF_SET_SLAVE(f)       do { (f) |= IFF_SLAVE; } while (0)
+#define IFF_SET_DYNAMIC(f)     do { (f) |= IFF_DYNAMIC; } while (0)
 
 #define IFF_CLR_UP(f)          do { (f) &= ~IFF_UP; } while (0)
 #define IFF_CLR_RUNNING(f)     do { (f) &= ~IFF_RUNNING; } while (0)
@@ -76,6 +80,8 @@
 #define IFF_CLR_POINTOPOINT(f) do { (f) &= ~IFF_POINTOPOINT; } while (0)
 #define IFF_CLR_MULTICAST(f)   do { (f) &= ~IFF_MULTICAST; } while (0)
 #define IFF_CLR_BROADCAST(f)   do { (f) &= ~IFF_BROADCAST; } while (0)
+#define IFF_CLR_SLAVE(f)       do { (f) &= ~IFF_SLAVE; } while (0)
+#define IFF_CLR_DYNAMIC(f)     do { (f) &= ~IFF_DYNAMIC; } while (0)
 
 #define IFF_IS_UP(f)          (((f) & IFF_UP) != 0)
 #define IFF_IS_RUNNING(f)     (((f) & IFF_RUNNING) != 0)
@@ -85,6 +91,8 @@
 #define IFF_IS_POINTOPOINT(f) (((f) & IFF_POINTOPOINT) != 0)
 #define IFF_IS_MULTICAST(f)   (((f) & IFF_MULTICAST) != 0)
 #define IFF_IS_BROADCAST(f)   (((f) & IFF_BROADCAST) != 0)
+#define IFF_IS_SLAVE(f)       (((f) & IFF_SLAVE) != 0)
+#define IFF_IS_DYNAMIC(f)     (((f) & IFF_DYNAMIC) != 0)
 
 /* We only need to manage the IPv6 bit if both IPv6 and IPv4 are supported.
  * Otherwise, we can save a few bytes by ignoring it.