#define SOLICIT 1
#define ADVERTISE 2
#define REQUEST 3
#define CONFIRM 4
#define RENEW 5
#define REBIND 6
#define REPLY 7
#define RELEASE 8
#define DECLINE 9
#define RECONFIGURE 10
#define INFORMATION_REQUEST 11
#define RELAY_FORW 12
#define RELAY_REPL 13
