Print Autonomous System Number in ASDOT notation
The ASN
(Autonomous System Number, and you can think it as port number) will be outputted in ASPLAIN
format by default. However, if -b
option is specified (code is here):
......
case 'b':
++ndo->ndo_bflag;
break;
......
The ASN
will be displayed in ASDOT
notation when the number is bigger than 65535
(code is here):
static char *
as_printf(netdissect_options *ndo,
char *str, int size, u_int asnum)
{
if (!ndo->ndo_bflag || asnum <= 0xFFFF) {
snprintf(str, size, "%u", asnum);
} else {
snprintf(str, size, "%u.%u", asnum >> 16, asnum & 0xFFFF);
}
return str;
}