You have a permanent connection to the internet. Your local network includes a web server and an SMTP server. You are concerned about hacking, so you set up port filtering on your network. Your local SMTP server has stopped sending or receiving messages through the internet, but your users can still access local and internet sites. What could be the possible cause?
A)Your DHCP server is down.
B)Your web server is filtering mail requests.
C)Your router is blocking port 25.
D)Your router is blocking port 110.

Question

Quizplus · Accepted Answer

The SMTP servers have stopped sending or receiving messages because the firewall is blocking port 25; unblock this port to activate the SMTP service.
Key Takeaway: In a network setup that has multiple network protocols and a firewall, it is important to have a clear checklist of the protocols that should be blocked or left open. It is crucial to check for the port numbers used in order to leave those ports open.

You Have a Permanent Connection to the Internet