A technician is troubleshooting a PC that is unable to perform DNS lookups.

DNS (Domain Name System) lookups are essential for translating human-friendly domain names into IP addresses that computers use to communicate. DNS typically uses port 53 for its communication.

In the provided firewall output, various ports are either allowed or blocked for outgoing traffic. For DNS recursion, which is the process of resolving domain names to IP addresses, port 53 must be open.

Port 53: This is the standard port used by DNS for queries and responses. The fact that it is currently blocked (as per the firewall output) is the reason why DNS lookups are failing. Opening port 53 will allow the DNS requests to pass through the firewall, enabling the resolution of domain names to IP addresses.

Other ports mentioned in the output are used for different services and protocols:

Port 1 is generally not used for standard services.

Port 445 is associated with SMB (Server Message Block) for file sharing in Windows environments.

Port 123 is used by NTP (Network Time Protocol) for time synchronization.

Port 80 is used for HTTP traffic, which is web traffic but not related to DNS lookups.