Actually, there could be a couple of problems. Your command line
Rate-limit input access-group rate-limit 100 26214400 26214400 26214400 conform-action transmit exceed-action drop
has "access-group rate-limit 100". Did you intend for that to be a rate-limit ACL 100 by MAC address? Or an IP extended ACL 100, where you can control the performance across ranges of IP addresses? Because the "rate-limit" part in there makes it go by MAC address.
Not a big deal, but the average rate you specified, 25*1024*1024=26214400 bits per second, is not a whole-number multiple of 8000. Which is what the rate-limit interface configuration command wants to see. If you enter this, the system will round it down to the nearest whole-number multiple of 8000, in this case 26208000.
What is a big deal though, is that your normal burst rate and excess burst rate are specified as identical to the average rate. But the rate-limit command treats the burst number values as bytes, not bits, so your burst values are 8 times too large. In your command line they should be entered as 26214400/8=3276800 bytes each.
Current Cisco documentation recommends that to achieve the configured average rate, you specify
normal burst = average rate * (1 byte)/(8 bits) * 1.5 seconds
extended burst = 2 * normal burst
So your rate-limit command should have numbers looking more like 26208000 4914000 9828000.
"With the listed choices for parameters, extensive test results have shown CAR to achieve the configured rate. If the burst values are too low, then the achieved rate is often much lower than the configured rate.
For more information about using CAR to police traffic, see the "Policing with CAR" section of the "Policing and Shaping Overview" in the Cisco IOS Quality of Service Configuration Guide."
Hope this helps.
