General steps for implementing ACLs

Procedure
  1. Configure at least one ACL. This creates and stores the ACL in the switch configuration.
  2. Assign an ACL. This applies the ACL to the inbound traffic on one or more designated interfaces.

CAUTION:

Regarding the use of source routing: source routing is enabled by default on the switch and can be used to override ACLs. For this reason, if you are using ACLs to enhance network security, the recommended action is to disable source routing on the switch. To do so, execute:

no ip source–route .