Index U

U

Unicast addresses, 77

Uninterruptible Power Supply (UPS), 462

Unnumbered links, 219–20

Unspecified address, 77

Upstream interface, 266

Upstream router, 267

URL protection systems, 347–48

User Datagram Protocol (UDP), 32–33

defined, 32

DHCP running over, 101

DNS running over, 110

header format, 32

session use, 507

SNMP running over, 36, 653

vulnerabilities, 308

User Priority Value (UPV), 587