A small office reports that internal users can access the internet but cannot resolve domain names to IP addresses. The DNS server is configured correctly. Which port should be checked on the firewall?
A company deploys a new internal application that uses a custom TCP port. The application fails to connect from client workstations. A technician verifies that the server is running and the firewall allows outbound traffic. Which step should the technician take next to identify the port issue?
A technician is troubleshooting a VoIP phone that cannot register with the SIP server. The phone has a valid IP address and can ping the server. Which port should be verified as open for SIP traffic?
A user cannot connect to a remote server using RDP. The network team confirms that the firewall allows outbound traffic on all ports. Which port is typically used for RDP and should be verified on the server side?
A technician is configuring a network monitoring tool that uses SNMP to query network devices. Which two ports should be allowed for SNMP communication?
A technician is configuring a new web server that must support both standard and encrypted web traffic. Which two ports should be opened in the firewall?
A technician is troubleshooting a legacy application that uses FTP for file transfers. The transfers work but are extremely slow. The network team mentions that the firewall is configured to inspect traffic on certain ports. Which port should be opened for FTP data transfer to improve performance?
A user reports that they can receive emails but cannot send any. The email client is configured with SMTP on port 25. The IT team confirms that port 25 is blocked by the ISP. Which alternative port should be used for SMTP submission?
A customer reports that they can browse the internet but cannot send or receive emails using their desktop email client. The email server is known to be working. Which port is most likely being blocked by a firewall?
A technician is troubleshooting a VoIP phone that intermittently drops calls. The phone uses SIP (Session Initiation Protocol) for signaling and RTP (Real-time Transport Protocol) for audio. Which ports are typically used by these protocols?
A customer reports that they cannot send emails from their desktop email client, but they can receive emails. The email server is running on the local network. Which port is most likely blocked on the firewall?
A technician is configuring a remote desktop solution for a user who needs to access their Windows workstation from home. Which port must be forwarded on the router for RDP (Remote Desktop Protocol)?
A company's internal DNS server is not resolving hostnames for clients. The technician verifies that the DNS service is running and the firewall allows traffic on port 53. However, clients still cannot resolve names. What is the most likely issue?
A technician is setting up a network printer that supports both LPD (Line Printer Daemon) and IPP (Internet Printing Protocol). The printer must be accessible from Windows and Linux clients. Which port should be opened for IPP?
A network administrator notices that a critical database server is responding slowly. The server uses both TCP and UDP for different services. Which of the following is a characteristic of UDP that could explain performance issues under heavy load?
A user reports that they cannot access a website hosted on a remote server. The technician finds that the firewall allows HTTP and HTTPS traffic, but the website uses a non-standard port. The user's browser shows 'connection refused'. Which tool can the technician use to verify if the remote port is open?
A security audit reveals that an internal file server is listening on multiple ports, including 137, 138, 139, and 445. The auditor recommends disabling older protocols. Which port is associated with SMB over TCP/IP directly (without NetBIOS)?
A user wants to access their company's webmail using a secure connection from a public Wi-Fi hotspot. The webmail server is configured to use IMAP over SSL. Which port should the email client use?
A small office uses a network printer that supports both IPP and LPD printing. The printer is configured to use the default port for IPP. Which port must be open on the firewall for printing to work?
During a security audit, a technician discovers that an internal web server is responding on port 8080 instead of the standard HTTP port. What is the most likely reason for this configuration?
A network administrator needs to allow secure remote administration of a router using SSH. The router is configured to use the default SSH port. Which port must be opened on the firewall?
A user needs to transfer files securely between two Linux servers over the internet. Which port should be allowed through the firewall for this purpose?
A user reports that they cannot send emails from their Outlook client, but they can receive emails. The email server is using standard ports. Which port is most likely blocked on the firewall?
A customer complains that their web browser cannot load any HTTPS websites, but HTTP sites work fine. The firewall is configured to allow common ports. Which port is most likely being blocked?
A technician is configuring a new database server that needs to accept remote connections from client applications using the default port for MySQL. Which port should be opened in the firewall?
A technician is troubleshooting a DHCP issue where clients are not receiving IP addresses. Which port must be open on the firewall for DHCP server communication?
During a network upgrade, a technician needs to allow remote desktop connections to Windows workstations from the internal network. Which port must be opened in the firewall?
More TCP & UDP Ports questions available in the full practice test.