See also:
https://www.rfc-editor.org/rfc/rfc4443#section-6.2
https://git.savannah.gnu.org/cgit/inetutils.git/commit/?id=c2cfa7889c09b6bd1ef7bc9967111e6509e610c7
---
 inet/netinet/icmp6.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/inet/netinet/icmp6.h b/inet/netinet/icmp6.h
index 249d2275d7..cfddb3e23d 100644
--- a/inet/netinet/icmp6.h
+++ b/inet/netinet/icmp6.h
@@ -78,6 +78,9 @@ struct icmp6_hdr
 #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_DST_UNREACH_POLICYFAIL  5 /* Source address failed
+                                           ingress/egress policy */
+#define ICMP6_DST_UNREACH_REJECTROUTE 6 /* Reject route to destination */
 
 #define ICMP6_TIME_EXCEED_TRANSIT     0 /* Hop Limit == 0 in transit */
 #define ICMP6_TIME_EXCEED_REASSEMBLY  1 /* Reassembly time out */
-- 
2.38.1