_ (PACKET_TOO_BIG_SENT, "packet too big response sent") \
_ (TTL_EXPIRE_SENT, "hop limit exceeded response sent") \
_ (PARAM_PROBLEM_SENT, "parameter problem response sent") \
- _ (DROP, "error message dropped")
+ _ (DROP, "error message dropped") \
+ _ (ALLOC_FAILURE, "buffer allocation failure")
typedef enum