Exam 312-50v12 topic 1 question 212 discussion

A large corporate network is being subjected to repeated sniffing attacks. To increase security, the company's IT department decides to implement a combination of several security measures. They permanently add the MAC address of the gateway to the ARP cache, switch to using IPv6 instead of IPv4, implement the use of encrypted sessions such as SSH instead of Telnet, and use Secure File Transfer Protocol instead of FTP. However, they are still faced with the threat of sniffing. Considering the countermeasures, what should be their next step to enhance network security?