Which of the following networking devices operates at Layer1?

A network administrator is looking at switch features and is unsure whether to purchase a model with PoE. Which of the following devices that commonly utilize PoE should the administrator consider? (Choose two.)

An IP address is maintained despite a failing UPS that causes a workstation to restart several times. Which of the following would allow this to occur?

A company just migrated its email service to a cloud solution. After the migration, two-thirds of the internal users were able to connect to their mailboxes, but the connection fails for the other one-third of internal users. Users working externally are not reporting any issues. The network administrator identifies the following output collected from an internal host:
c:\user> nslookup newmail.company.com
Non-Authoritative answer:
Name: newmail.company.com
IPs: 3.219.13.186, 64.58.225.184, 184.168.131.243
Which of the following verification tasks should the network administrator perform NEXT?

An organization requires the ability to send encrypted email messages to a partner from an email server that is hosted on premises. The organization prefers to use the standard default ports when creating firewall rules. Which of the following ports should be open to satisfy the requirements?