Rackspace Technology Network Security Administrator interview questions

I applied online and HR called me back to set an appointment for a phone interview with another HR recruiter, they were very punctual with their phone call, they asked some usual questions about what my responsibilities were in my previous job, if I knew anything about the company, why was I looking for another job, and the second part was technical questions. Such as How do you connect remotely to a Linux server, What's the difference between Telnet and SSH, What are the advantages or what is VPN, what is IPsec? Why is a stateful firewall better? For IPsec what would I choose ESP or AH and why?