Index_U

U

UDP (User Datagram Protocol), 226

UNC (Universal Naming Convention), 49, 228

Unicode Transformation Format 8 (UTF-8), 375

Uniform Resource Locators (URLs). See URLs (Uniform Resource Locators)

Uninterruptible power supply (UPS), power losses and spikes and, 9

UNIX directory style, 242

unresolved recipients, e-mail, 297

update sites, Web servers, 93–94

upload sites, FTP, 228–30

UPS (Uninterruptible power supply), power losses and spikes and, 9

URLs (Uniform Resource Locators), 29–32

authentication, 3

browser redirection, 77

domains specified with, 29–30

load balancers and, 117

overview of, 29

reserved characters and meanings, 31

special characters and formats, 30–31

SSL and, 184

Web site identification, 49

user access. See access logs

user accounts, 148–49, 155

User Authentication field, common log file format, 367

User Datagram Protocol (UDP), 226

user isolation, FTP sites, 232–33

user sessions, SMTP virtual servers, 264–65

user statistics, FTP sites, 244–45

UTF-8 (Unicode Transformation Format 8), 375