Index D

D

Data collection models, 568

Data Collection Modules (DCMs), 655

Datagrams, 553

Data Link Layer (OSI reference model), 18

Data Link Layer (TCP/IP protocol suite), 28–29

defined, 27

LLC sublayer, 29

Mac sublayer, 28–29

Data replication/disk mirroring, 399

Data Service Units (DSUs), 40–41

Dead host detection, 507

DECbit, 499

Decentralized model, 22

Dedicated VPNs, 352, 356

Default routes, 166

Demand circuits, 185–86

acknowledgments/retransmissions, 185–86

defined, 185

flow control, 186

presumption of reachability, 185

triggered updates, 185

Demilitarized Zone (DMZ), 37

Democratic model, 518

Denial of Service (DOS), 307

Dense distribution model, 255

Dense-mode PIM (PIM-DM), 276–78

conditions for use, 276–77

defined, 276

illustrated, 277

operations, 277–78

PIM-SM vs., 280

See also PIM

Dense Wave Division Multiplexing (DWDM), 400

Deployment, 14

Design. See Network design

Designated forwarder

defined, 267

DVMRP, 271

OSPF, 201–2

Designated Router (DR), 201–2

election of, 202

LSA generation by, 275

misconception, 201

purpose, 201

Desktop management, 431–32

Detailed Requirements Specification, 7–8

Deterministic flow hashing, 515, 516

Dial on Demand Routing (DDR), 420

Dial VPNs, 351, 353–55

client-initiated, 354–55

defined, 351

NAS-initiated, 355

operation, 355

service providers and, 354

See also Virtual Private Networks (VPNs)

Differentiated Services (DS), 563–64, 617–23

advantage, 618

architecture, 619

boundary nodes, 620–22

byte format, 619

CBR with, 626

design considerations, 620–23

domains, 620

goal, 618

interior nodes, 622–23

with IPSec, 626

PHB, 619–20

RSVP with, 624–25

service marking, 618–19

source domains, 623

specifications, 617

summary, 629

traffic conditioner, 621–22

Diffie-Helman (D-H) model, 321

Diffusing Update Algorithm (DUAL), 164–65

Dig, 693–94

Digital signatures, 324, 372–73

Directed broadcast, 64–65

Direct interface routing, 166

Directory-Enabled Network (DEN), 131

Directory Service Markup Language (DSML), 126

Directory services, 122–31

benefits, 122

client/server model, 124

defined, 122

DEN and, 131

LDAP and, 126–31

name services and, 123

networked file systems and, 123

RDBMSs and, 123–24

relational databases and, 123

uses, 123

when not to use, 124–25

X.500 standard, 125–26

Disaster recovery

data replication/disk mirroring, 399

defined, 394

electronic vaulting, 398

models, 398–401

outsourced, 401

SANs/OSNs, 400

server mirroring/clustering, 399

tape/CD site backup, 398

Disaster Recovery (DR) plan

approach, 397–98

defined, 397

development, 395–401

Disk compression, 542–43

Disk mirroring, 458–59

Distance-Vector Multicast Routing Protocol. See DVMRP

Distance-vector routing algorithms, 161–65

convergence, 172

defined, 161

flooded updates, 163

hybrid, 164–65

link-state routing vs., 162–65

RIP routing enhancements, 186–87

See also Routing protocols

Distributed hashing techniques, 518–19

Distributed load-sharing algorithms, 505–6

Distributed model, 23–24

CORBA, 23, 24

defined, 22

IIOP, 24

Documentation, 13–14

Domain names, 108–10

format, 109–10

FQDNs, 110

hierarchy, 109

registration, 110

SLDs, 110

TDLs, 108, 109, 110

Domain Name System (DNS), 107–21

access, 107

administrator, 113

caching, 117, 120

components, 110–14

defined, 36, 107

Domain Name Space, 111

dynamic, 119

extensions, 108

implementing, 117–19

inverse query operation, 116–17

ISP maintained primary and locally maintained secondary service, 118–19

ISP maintained primary/secondary service, 117–18

load sharing, 507–9

load-sharing proxies, 454

locally maintained primary/secondary service, 118

mapping names to addresses, 116

name resolvers, 113–14

name servers, 112–13

operations, 114–17

performance, 120–21

queries, 113

query operation, 114–15

resilience, 119

Resource Records (RR), 111–12

running over UDP or TCP, 110

SOHO configurations and, 121

split, 119

structure, 108

vulnerabilities, 310–11

Domains

DS, 620

source, 623

tree hierarchy, 112

zone relationship, 113

Downstream interfaces, 266

Downtime cost, 394–95

example, 396

financial models, 395

Dual-Modular Redundancy (DMR), 436

Dual port transceivers, 430–31

DVMRP, 264–72

building multicast trees, 268–71

defined, 264

designated forwarder, 271

design issues, 272

field definitions, 265–66

functioning of, 265

grafting, 271

interoperability, 283

message format, 265–66

multicast network running, 270

operation, 266–72

pruning, 269–70

routers, 268, 371

routing process, 267–68

terminology, 266–67

timers, 267

tunneling, 271–72

versions, 272

See also Multicast routing

Dynamic Address Translation (DAT), 134

Dynamic DNS, 119

Dynamic Host Configuration Protocol (DHCP), 95–102

address allocation, 96

allocating new network address, 97

BOOTP concurrent use, 102

client/server interaction, 98–100

defined, 95

features, 95

field definitions, 97–98

lease renewal, 100–101

message format, 96–97

operations, 97–101

running over UDP, 101

Safe Failover Protocol, 102

Dynamic router discovery, 174

Dynamic routing entries, 166



Data Networks. Routing, Seurity, and Performance Optimization
ActionScripting in Flash MX
ISBN: N/A
EAN: 2147483647
Year: 2001
Pages: 117

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