diff --git a/include/net/if_arp.h b/include/net/if_arp.h
index 2ffc3055..14b54f19 100644
--- a/include/net/if_arp.h
+++ b/include/net/if_arp.h
@@ -40,6 +40,7 @@
 #define ARPHRD_CSLIP6   129
 #define ARPHRD_PPP      130
 #define ARPHRD_LOOPBACK 131
+#define ARPHRD_SIT      132		/* sit0 device - IPv6-in-IPv4.  */
 
 struct arphdr {
 	unsigned short int ar_hrd;		/* Format of hardware address.  */
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
new file mode 100644
index 00000000..b5806d3a
--- /dev/null
+++ b/include/net/ip6_route.h
@@ -0,0 +1,38 @@
+/*
+ * Phoenix-RTOS
+ *
+ * libphoenix
+ *
+ * net/ip6_route.h
+ *
+ * Copyright 2024 Phoenix Systems
+ * Author: Mateusz Kobak
+ *
+ * This file is part of Phoenix-RTOS.
+ *
+ * %LICENSE%
+ */
+
+
+#ifndef _NET_IP6_ROUTE_H_
+#define _NET_IP6_ROUTE_H_
+
+#include <netinet/in.h>
+
+/* Needed by route.c in busybox */
+struct in6_rtmsg
+{
+    struct in6_addr rtmsg_dst;
+    struct in6_addr rtmsg_src;
+    struct in6_addr rtmsg_gateway;
+    uint32_t rtmsg_type;
+    uint16_t rtmsg_dst_len;
+    uint16_t rtmsg_src_len;
+    uint32_t rtmsg_metric;
+    unsigned long int rtmsg_info;
+    uint32_t rtmsg_flags;
+    int rtmsg_ifindex;
+};
+
+
+#endif /* _NET_IP6_ROUTE_H_ */
diff --git a/include/net/route.h b/include/net/route.h
index 465a01f4..0473ecb2 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -13,6 +13,9 @@
 #define RTF_WINDOW      0x0080
 #define RTF_IRTT        0x0100
 #define RTF_REJECT      0x0200
+#define RTF_DEFAULT     0x0400
+#define RTF_ADDRCONF    0x0800
+#define RTF_CACHE       0x1000
 #define RTF_NONEXTHOP   0x00200000
 
 
diff --git a/include/netinet/icmp6.h b/include/netinet/icmp6.h
new file mode 100644
index 00000000..70ab305e
--- /dev/null
+++ b/include/netinet/icmp6.h
@@ -0,0 +1,64 @@
+/*
+ * Phoenix-RTOS
+ *
+ * libphoenix
+ *
+ * netinet/icmp6.h
+ *
+ * Copyright 2024 Phoenix Systems
+ * Author: Mateusz Kobak
+ *
+ * This file is part of Phoenix-RTOS.
+ *
+ * %LICENSE%
+ */
+
+#ifndef _NETINET_ICMP6_H
+#define _NETINET_ICMP6_H
+
+#include <stdint.h>
+
+
+struct icmp6_hdr {
+	uint8_t icmp6_type;   /* type field */
+	uint8_t icmp6_code;   /* code field */
+	uint16_t icmp6_cksum; /* checksum field */
+	union {
+		uint32_t icmp6_un_data32[1]; /* type-specific field */
+		uint16_t icmp6_un_data16[2]; /* type-specific field */
+		uint8_t icmp6_un_data8[4];   /* type-specific field */
+	} icmp6_dataun;
+};
+
+#define icmp6_data32   icmp6_dataun.icmp6_un_data32
+#define icmp6_data16   icmp6_dataun.icmp6_un_data16
+#define icmp6_data8    icmp6_dataun.icmp6_un_data8
+#define icmp6_pptr     icmp6_data32[0] /* parameter prob */
+#define icmp6_mtu      icmp6_data32[0] /* packet too big */
+#define icmp6_id       icmp6_data16[0] /* echo request/reply */
+#define icmp6_seq      icmp6_data16[1] /* echo request/reply */
+#define icmp6_maxdelay icmp6_data16[0] /* mcast group membership */
+
+#define ICMP6_DST_UNREACH    1
+#define ICMP6_PACKET_TOO_BIG 2
+#define ICMP6_TIME_EXCEEDED  3
+#define ICMP6_PARAM_PROB     4
+
+#define ICMP6_ECHO_REQUEST     128
+#define ICMP6_ECHO_REPLY       129
+#define MLD_LISTENER_QUERY     130
+#define MLD_LISTENER_REPORT    131
+#define MLD_LISTENER_REDUCTION 132
+
+#define ICMP6_DST_UNREACH_NOROUTE 0 /* no route to destination */
+#define ICMP6_DST_UNREACH_ADMIN   1 /* administratively prohibited */
+
+#define ICMP6_DST_UNREACH_BEYONDSCOPE 2 /* beyond scope of source address */
+#define ICMP6_DST_UNREACH_ADDR        3 /* address unreachable */
+#define ICMP6_DST_UNREACH_NOPORT      4 /* bad port */
+
+#define ICMP6_TIME_EXCEED_TRANSIT    0 /* Hop Limit == 0 in transit */
+#define ICMP6_TIME_EXCEED_REASSEMBLY 1 /* Reassembly time out */
+
+
+#endif /* _NETINET_ICMP6_H */
diff --git a/include/netinet/in.h b/include/netinet/in.h
index d86079d9..8c45baff 100644
--- a/include/netinet/in.h
+++ b/include/netinet/in.h
@@ -63,6 +63,7 @@ enum {
 	IPPROTO_GRE = 47,
 	IPPROTO_ESP = 50,
 	IPPROTO_AH = 51,
+	IPPROTO_ICMPV6 = 58,
 	IPPROTO_SCTP = 132,
 	IPPROTO_UDPLITE = 136,
 	IPPROTO_RAW = 255,
diff --git a/include/sys/sockdefs.h b/include/sys/sockdefs.h
index 4dca1d4e..b0e047c2 100644
--- a/include/sys/sockdefs.h
+++ b/include/sys/sockdefs.h
@@ -19,4 +19,13 @@
 #define SOCK_NONBLOCK 0x8000
 #define SOCK_CLOEXEC  0x4000
 
+#define SOL_IPV6 41 /* IPPROTO_IPV6 */
+#define SOL_RAW 255 /* IPPROTO_RAW */
+
+/*
+ * Options for level IPPROTO_IPV6
+ */
+#define IPV6_CHECKSUM       7
+#define IPV6_V6ONLY         27
+
 #endif