seq rule option is used to check that the TCP header sequence number is less than, greater than, equal to, not equal to, less than or equal to, or greater than or equal to a specified integer value. This rule option can also check that the sequence number is between a range of numbers, using the
<> range operator for an exclusive range check or the
<=> for an inclusive one.
Single value comparison:
# Look for a sequence number of 0 seq:0;