An administrator has taken steps to secure a SOHO wired network, but as a result the users report that they can no longer access the Internet but can still see other computers on the network. Which…

Port 80 is the default port for HTTP, the protocol used by web browsers to retrieve pages from Internet servers. Blocking outbound port 80 at the router or firewall drops all standard web requests before they leave the local network. LAN communication uses different protocols (NetBIOS, SMB) on different ports, so local resource access continues to function normally even when port 80 is closed.

Port 3389 is used by Remote Desktop Protocol (RDP); enabling it opens inbound remote access but does not affect outbound HTTP browsing or Internet access.

MAC filtering controls which physical devices are permitted on the network and would prevent a filtered device from accessing anything, not selectively block Internet while allowing LAN access.

LDAP (port 389) is used for directory service lookups such as Active Directory authentication; disabling it would affect login and directory queries, not general Internet browsing.