Unauthenticated Access protocol 357
unauthenticated access for wireless LANs 572
unauthorized addresses 25
unauthorized DHCP servers 84
unicast 6to4 addresses 52
unicast global addresses 50
unicast IPv4 addresses 16
unicast IPv6 addresses 50–53
unicast ISATAP addresses 52
unicast link-local addresses 51
unicast loopback addresses 51
unicast site-local addresses 51
unicast unspecified addresses 51
unnumbered connections for remote site connectivity 509
upgrading DHCP server hardware 72–73
upgrading to Windows Server 2003 See migrating to Windows Server 2003
user accounts and groups
choosing router 493–499
configuring for Active Directory 523–524
configuring for IAS RADIUS servers 364
user authentication 488–490
user certificates
See also certificates
distributing through autoenrollment for wireless LANs 576
installing for remote site-to-site connections 527
installing on wireless clients 584–587
user-defined classes, DHCP 91
user-level authentication 488–490