Samsung Multifunction Printer Error Code S6-3128

Error code S6-3128 on a Samsung multifunction printer indicates a failure during 802.1x network authentication. The 802.1x protocol is an IEEE standard for port-based network access control, commonly used in enterprise and institutional environments to authenticate devices before granting them access to the network. When this error appears, the printer has attempted to authenticate with the network's RADIUS or similar authentication server and was rejected. The rejection occurs at the confirmation stage, meaning the server received the request but refused to validate the printer's credentials or found a mismatch in the submitted information.

The root cause typically falls into one of two categories: incorrect server configuration on the printer side, or a mismatch between the authentication protocol the printer is using and the protocol the server expects. Common 802.1x protocols include EAP-TLS, PEAP, and EAP-TTLS, and the printer must be configured to use the exact protocol supported by the authentication server. User credentials such as the username and password submitted during authentication must also match exactly what the server has on record. A single character difference or an expired password will produce this error.

Diagnosis begins by accessing the printer's network settings and reviewing the 802.1x configuration. The server address, authentication protocol selection, username, and password should all be verified against the current network policy set by the network administrator. If the network infrastructure was recently updated or if user credentials were changed, the printer settings will need to be updated to match. No hardware components are typically involved in this error; it is a configuration and credentials issue resolved through software settings.