A qustion about DAI packet tracer

Dear Rene’
I need your help please : Following the packet tracer of DAI in this further link : https://networklessons.com/switching/dai-dynamic-arp-inspection , there is an important line : SW1(config)#ip arp inspection vlan 123
however it is not working at all : I use a 7.2 version of packet tracer (the latest) , but the CLI show en error below the word arp.
I wonder why. Please try to figure this out

A post was merged into an existing topic: DAI (Dynamic ARP Inspection)