extern void igmp_print(const u_char *, u_int);
extern void igrp_print(const u_char *, u_int, const u_char *);
extern void ip_print(const u_char *, u_int);
extern void igmp_print(const u_char *, u_int);
extern void igrp_print(const u_char *, u_int, const u_char *);
extern void ip_print(const u_char *, u_int);