There are many methods, and the common ones are:
1、Find out the IP to limit the port speed (this is more troublesome)
2、Use NBAR (very easy to use)
However, restarting requires re-calling the file tftp://130.130.122.123/, so it is better to use flash card. If the file is not called, then there will be no match protocol bittorrent
ip nbar pdlm tftp://130.130.122.123/
class-map match-all bit
match protocol bittorrent
policy-map limit-bit
class bit
police cir 240000
conform-action transmit
exceed-action drop
police cir 8000
conform-action transimit
exceed-action drop
interface fastethernet 0/1
service-policy input limit-bit (download)
service-policy output limit-bit (upload)
ip nat outside
interface fastethernet 0/0
ip nat inside
ip nat inside list 1 pool nbar-pool overload
access-list 1 permit any
ip nat pool nbar-pool
8000 < 1k
80000 < 4k 5k, 5k 5k
160000 < 16K, 13K
240000 <=22k, 24K
800000 <=80K <100K