Networks, Cables, OSI, and TCP Models
CSMA/CD, Switching, and VLANs
Trunking, DTP, and Inter-VLAN Routing
Router and Switch Security
Network Address Translation
This feature has been disabled by the administrator
Nine times out of ten, the router administrator has forgotten to add the IP NAT outside or IP NAT inside command to the router interfaces. In fact, this is almost always the problem! The next most frequent mistakes include the wrong ACL and a misspelled pool name (it is case sensitive).