2000 introduces a client-side DNS caching service. When the Windows DNS resolver receives a query response, the DNS resource record is added to a cache. When it queries the same resource record name again and it is found in the cache, then the resolver does not query the DNS server. This speeds up DNS query time and reduces network traffic. Server family features The Windows 2000 Server family consists of Windows 2000 Server, Windows 2000 Advanced Server, Windows 2000 Small Business Server, and Windows 2000 Datacenter Server. All editions of Windows 2000 Server have the following services and features built in: Routing and Remote Access Service (RRAS) support, facilitating dial-up and VPN connections using IPsec, L2TP or L2TP/IPsec, support for RADIUS authentication in Internet Authentication Service, network connection sharing, Network Address Translation, unicast and multicast routing schemes. Remote access security features: Remote Access Policies for setup, verify Caller ID (IP address for VPNs), callback and Remote access account lockout Autodial by location feature using the Remote Access Auto Connection Manager service Extensible Authentication Protocol support in IAS (EAP-MD5 and EAP-TLS) later upgraded to PEAPv0/EAP-MSCHAPv2 and PEAP-EAP-TLS in Windows 2000 SP4 DNS server, including support for Dynamic DNS. Active Directory relies heavily on DNS. IPsec support and TCP/IP filtering Smart card support Microsoft Connection Manager Administration Kit (CMAK) and Connection Point Services Support for distributed file systems (DFS) Hierarchical Storage Management support including remote storage, a service that runs with NTFS and automatically transfers files that are not used for some time to less expensive storage media Fault tolerant volumes, namely Mirrored and RAID-5 Group Policy (part of Active Directory) IntelliMirror, a collection of technologies for fine-grained management of Windows 2000 Professional clients that duplicates users' data, applications, files, and settings in a centralized location on the network. IntelliMirror employs technologies such as Group Policy, Windows Installer, Roaming profiles, Folder Redirection, Offline Files (also known as Client Side Caching or CSC), File Replication Service (FRS), Remote Installation Services (RIS) to address desktop management scenarios such as user data management, user settings management, software installation and maintenance. COM+, Microsoft Transaction Server and Distributed Transaction Coordinator MSMQ 2.0 TAPI 3.0 Integrated Windows Authentication (including Kerberos, Secure channel and SPNEGO (Negotiate) SSP packages for Security Support Provider Interface (SSPI)). MS-CHAP v2 protocol Public Key Infrastructure (PKI) and Enterprise Certificate Authority support Terminal Services and support for the Remote Desktop Protocol (RDP) Internet Information Services