nly once. When you apply commands to an interface range, the parser will replicate the commands on each interface within the range. On a switch with 96 inter- faces, this can save hours of time-especially during initial configurations. Interface ranges are composed of lists of interfaces. You can specify interfaces individ- ually or grouped in concurrent ranges. Individual interfaces are separated by commas, Interface Ranges while ranges are shown as the starting and ending interfaces, separated by hyphens. Here, I'm accessing the two interfaces g1/0/10 and g1/0/12: 8750(config)#interface range g1/0/10 , g1/0/12 3750(config-if-range)# Once you're in config-if-range configuration mode, all commands you enter will be applied to every interface you've included in the specified range. Here, I'm accessing the range of ports g1/0/10 through (and including) g1/0/12. When specifying a range, for the second value I only need to include the significant value from the interface. That is, I don't need to type g/1/0/10 - g1/0/12, but only g1/0/10 - 12: 8750(config)#interface range g1/0/10 - 12 750(config-if-range)# To reference multiple ranges, separate them with commas. Here, I'm referencing the ranges g1/0/10 through g1/0/12 and g1/0/18 through g1/0/20: 3750(config)#interface range g1/0/10 - 12 , g1/0/18 - 20 3750(config-if-range)# Not only can you specify lists of interfaces, but you can save lists of interfaces for future reference. To do this, define the interface range with the define interface-range macro- name command. Here, I've created a macro called Servers: 3750(config)#define interface-range Servers g1/0/10 , g1/0/12 - 14 3750(config)# Don't confuse these macros with another feature, called smartport mac- ros (covered next). The two features are unrelated. To make matters even more confusing, you can apply a smartport macro to an interface- range macro. For the programmers out there, smartport macros are probably closer to the macros you're used to. Once you've defined an interface-range macro, you can reference 