diff --git a/src/core/ip.c b/src/core/ip.c
index 6e868d1f..af6e36b3 100644
--- a/src/core/ip.c
+++ b/src/core/ip.c
@@ -37,15 +37,15 @@
  */
 
 /**
+ * @defgroup ip4 IPv4
+ *
+ * @defgroup ip6 IPv6
+ * 
  * @defgroup ipaddr IP address handling
- */
-
-/**
+ * 
  * @defgroup ip4addr IPv4 only
  * @ingroup ipaddr
- */
-
-/**
+ * 
  * @defgroup ip6addr IPv6 only
  * @ingroup ipaddr
  */
diff --git a/src/core/ipv4/autoip.c b/src/core/ipv4/autoip.c
index a478f0ae..8ca26712 100644
--- a/src/core/ipv4/autoip.c
+++ b/src/core/ipv4/autoip.c
@@ -64,6 +64,7 @@
 
 /**
  * @defgroup autoip AUTOIP
+ * @ingroup ip4
  * AUTOIP related functions
  * @see netifapi_autoip
  */
diff --git a/src/core/ipv4/dhcp.c b/src/core/ipv4/dhcp.c
index d63aea83..b3307dac 100644
--- a/src/core/ipv4/dhcp.c
+++ b/src/core/ipv4/dhcp.c
@@ -67,6 +67,7 @@
 
 /**
  * @defgroup dhcp4 DHCPv4
+ * @ingroup ip4
  * DHCP (IPv4) related functions
  * @see netifapi_dhcp4
  */
diff --git a/src/core/ipv4/igmp.c b/src/core/ipv4/igmp.c
index 4e8d25e2..50c5d9d0 100644
--- a/src/core/ipv4/igmp.c
+++ b/src/core/ipv4/igmp.c
@@ -38,6 +38,12 @@
  * source code.
 */
 
+/**
+ * @defgroup igmp IGMP
+ * @ingroup ip4
+ * To be called from TCPIP thread
+ */
+
 /*-------------------------------------------------------------
 Note 1)
 Although the rfc requires V1 AND V2 capability
@@ -477,6 +483,7 @@ igmp_input(struct pbuf *p, struct netif *inp, const ip4_addr_t *dest)
 }
 
 /**
+ * @ingroup igmp
  * Join a group on one network interface.
  *
  * @param ifaddr ip address of the network interface which should join a new group
@@ -513,6 +520,7 @@ igmp_joingroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr)
 }
 
 /**
+ * @ingroup igmp
  * Join a group on one network interface.
  *
  * @param netif the network interface which should join a new group
@@ -571,6 +579,7 @@ igmp_joingroup_netif(struct netif *netif, const ip4_addr_t *groupaddr)
 }
 
 /**
+ * @ingroup igmp
  * Leave a group on one network interface.
  *
  * @param ifaddr ip address of the network interface which should leave a group
@@ -606,6 +615,7 @@ igmp_leavegroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr)
 }
 
 /**
+ * @ingroup igmp
  * Leave a group on one network interface.
  *
  * @param netif the network interface which should leave a group
diff --git a/src/core/ipv6/mld6.c b/src/core/ipv6/mld6.c
index cb1b71d7..ef854e76 100644
--- a/src/core/ipv6/mld6.c
+++ b/src/core/ipv6/mld6.c
@@ -1,8 +1,5 @@
 /**
  * @file
- *
- * Multicast listener discovery for IPv6. Aims to be compliant with RFC 2710.
- * No support for MLDv2.
  */
 
 /*
@@ -40,6 +37,14 @@
  * <delamer@inicotech.com>
  */
 
+/**
+ * @defgroup mld6 MLD6
+ * @ingroup ip6
+ * Multicast listener discovery for IPv6. Aims to be compliant with RFC 2710.
+ * No support for MLDv2.\n
+ * To be called from TCPIP thread
+ */
+
 /* Based on igmp.c implementation of igmp v2 protocol */
 
 #include "lwip/opt.h"
@@ -310,6 +315,7 @@ mld6_input(struct pbuf *p, struct netif *inp)
 }
 
 /**
+ * @ingroup mld6
  * Join a group on a network interface.
  *
  * @param srcaddr ipv6 address of the network interface which should
@@ -343,6 +349,7 @@ mld6_joingroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
 }
 
 /**
+ * @ingroup mld6
  * Join a group on a network interface.
  *
  * @param netif the network interface which should join a new group.
@@ -381,6 +388,7 @@ mld6_joingroup_netif(struct netif *netif, const ip6_addr_t *groupaddr)
 }
 
 /**
+ * @ingroup mld6
  * Leave a group on a network interface.
  *
  * @param srcaddr ipv6 address of the network interface which should
@@ -414,6 +422,7 @@ mld6_leavegroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
 }
 
 /**
+ * @ingroup mld6
  * Leave a group on a network interface.
  *
  * @param netif the network interface which should leave the group.