The LAN Manager (LM) is a group of early Microsoft client/server software products that enable users to connect personal computers on a single network. Its features include transparent file and printer sharing, user security features, and network administration tools. In Active Directory domains, the default authentication protocol is the Kerberos protocol. However, if Kerberos is not available for any reason, LM, NTLM, or NTLMv2 can be used as an alternative.

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