Methods and systems for providing vendor agnostic captive portal authentication in a network that includes a plurality of network access devices are provided. For instance, one method includes receiving a redirect request for a communication between a first user-terminal and a first network access device, the redirect request including at least one of a vendor-specific item of information of the first network access device and an Internet Protocol (IP) address of the first network access device. The method further includes comparing the at least one of the vendor-specific item of information of the first network access device and the IP address of the first network access device against each of a plurality of entries of a network access device database, and providing the first user-terminal access to a captive portal page in response to an appropriate match.