Analysis MIB variable expression. The expression can be any expression comprised of local or remote (MLM only) node MIB variables with the following high to low precedence and left to right associativity of operators: () : grouping - : unary minus * : multiplication, / : division, % : remainder + : addition, - : subtraction << : bitwise left shift, >> : bitwise right shift & : bitwise AND ^ : bitwise exclusive OR | : bitwise inclusive OR Expression evaluation/operators are based on standard c program execution. Counter MIB variables default to the delta value, calculated by subtracting the old MIB value from the current MIB value. Integer and gauge MIB variables default to the current value returned. The two functions @delta() and @value() can be used to override the above defaults. Displaystrings can be converted to a real value using the @delta() and @value() functions. Built-in functions available within expressions include: @sum(MIB variable expression, MIB variable expression, ...) - returns the sum of all values. @avg(MIB variable expression, MIB variable expression, ...) - returns the average of all values. @min(MIB variable expression, MIB variable expression, ...) - returns the minimum of all values. @max(MIB variable expression, MIB variable expression, ...) - returns the maximum of all values. @diff(MIB variable expression, MIB variable expression) - returns the positive difference in the two expressions. @delta(MIB variable expression) - uses the delta value calculated by subtracting the last returned MIB variable value from the current MIB variable value. This function can be used to force delta calculations on integer, gauge, and displaystring MIB variables. @value(MIB variable expression) - uses the current MIB variable value. This function can be used to force the use of actual values for counter MIB variables. @numInst(MIB variable expression) - returns the number of instances found for the MIB variable expression. @abs(MIB variable expression) - returns the positive value of the expression. @rand() - returns a random number between 0 and 42949667295. To use remote MIB variables, the alias name, host name, or IP address can be pre-appended to the MIB variable binding. Also, the object ID can accept a wildcard value (*). When MIB variables resolve to multiple values or nodes outside of the built-in functions, all resolved values are averaged before use in the expression. For example, routers:.1.2.3.4.5.0/100, would result in the averaging of all values returned for this aliased MIB variable before the division by 100 operation is performed.