D-Link DFL-260 Product Manual - Page 82

Services, 3.2.1. Overview, A Service is Passive, Predefined Services - allow ftp

Page 82 highlights

3.2. Services Chapter 3. Fundamentals 3.2. Services 3.2.1. Overview A Service object is a reference to a specific IP protocol with associated parameters. A service definition is usually based on one of the major transport protocols such as TCP or UDP which is associated with a specific source and/or destination port number(s). For example, the HTTP service is defined as using the TCP protocol with the associated destination port 80 and any source port. However, service objects are not restricted to just the TCP or UDP protocols. They can be used to encompass ICMP messages as well as a user-definable IP protocol. A Service is Passive Services are passive NetDefendOS objects in that they do not themselves carry out any action in the configuration. Instead, service objects must be associated with the security policies defined by various NetDefendOS rule sets and then act as a filter to apply those rules only to a specific type of traffic. For example, an IP rule in a NetDefendOS IP rule set has a service object associated with it as a filtering parameter to decide whether or not to allow a specific type of traffic to traverse the NetDefend Firewall. Inclusion in IP rules is one the most important usage of service objects and it is also how ALGs become associated with IP rules since an ALG is associated with a service and not directly with an IP rule. For more information on how service objects are used with IP rules, see Section 3.5, "IP Rule Sets". Predefined Services A large number of service objects are predefined in NetDefendOS. These include common services such as HTTP, FTP, Telnet and SSH. Predefined services can be used and also modified just like custom, user defined services. However, it is recommended to NOT make any changes to predefined services and instead create custom services with the desired characteristics. Custom service creation in detail later in Section 3.2.2, "Creating Custom Services". Example 3.6. Listing the Available Services To produce a listing of the available services in the system: Command-Line Interface gw-world:/> show Service The output will look similar to the following listing with the services grouped by type with the service groups appearing first: ServiceGroup Name -----------all_services all_tcpudp ipsec-suite l2tp-ipsec l2tp-raw pptp-suite Comments All ICMP, TCP and UDP services All TCP and UDP services The IPsec+IKE suite L2TP using IPsec for encryption and authentication L2TP control and transport, unencrypted PPTP control and transport ServiceICMP 82

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
  • 201
  • 202
  • 203
  • 204
  • 205
  • 206
  • 207
  • 208
  • 209
  • 210
  • 211
  • 212
  • 213
  • 214
  • 215
  • 216
  • 217
  • 218
  • 219
  • 220
  • 221
  • 222
  • 223
  • 224
  • 225
  • 226
  • 227
  • 228
  • 229
  • 230
  • 231
  • 232
  • 233
  • 234
  • 235
  • 236
  • 237
  • 238
  • 239
  • 240
  • 241
  • 242
  • 243
  • 244
  • 245
  • 246
  • 247
  • 248
  • 249
  • 250
  • 251
  • 252
  • 253
  • 254
  • 255
  • 256
  • 257
  • 258
  • 259
  • 260
  • 261
  • 262
  • 263
  • 264
  • 265
  • 266
  • 267
  • 268
  • 269
  • 270
  • 271
  • 272
  • 273
  • 274
  • 275
  • 276
  • 277
  • 278
  • 279
  • 280
  • 281
  • 282
  • 283
  • 284
  • 285
  • 286
  • 287
  • 288
  • 289
  • 290
  • 291
  • 292
  • 293
  • 294
  • 295
  • 296
  • 297
  • 298
  • 299
  • 300
  • 301
  • 302
  • 303
  • 304
  • 305
  • 306
  • 307
  • 308
  • 309
  • 310
  • 311
  • 312
  • 313
  • 314
  • 315
  • 316
  • 317
  • 318
  • 319
  • 320
  • 321
  • 322
  • 323
  • 324
  • 325
  • 326
  • 327
  • 328
  • 329
  • 330
  • 331
  • 332
  • 333
  • 334
  • 335
  • 336
  • 337
  • 338
  • 339
  • 340
  • 341
  • 342
  • 343
  • 344
  • 345
  • 346
  • 347
  • 348
  • 349
  • 350
  • 351
  • 352
  • 353
  • 354
  • 355
  • 356
  • 357
  • 358
  • 359
  • 360
  • 361
  • 362
  • 363
  • 364
  • 365
  • 366
  • 367
  • 368
  • 369
  • 370
  • 371
  • 372
  • 373
  • 374
  • 375
  • 376
  • 377
  • 378
  • 379
  • 380
  • 381
  • 382
  • 383
  • 384
  • 385
  • 386
  • 387
  • 388
  • 389
  • 390
  • 391
  • 392
  • 393
  • 394
  • 395
  • 396
  • 397
  • 398
  • 399
  • 400
  • 401
  • 402
  • 403
  • 404
  • 405
  • 406
  • 407
  • 408
  • 409
  • 410
  • 411
  • 412
  • 413
  • 414
  • 415
  • 416
  • 417
  • 418
  • 419
  • 420
  • 421
  • 422
  • 423
  • 424
  • 425
  • 426
  • 427
  • 428
  • 429
  • 430
  • 431
  • 432
  • 433
  • 434
  • 435
  • 436
  • 437
  • 438
  • 439
  • 440
  • 441
  • 442
  • 443
  • 444
  • 445
  • 446
  • 447
  • 448
  • 449
  • 450
  • 451
  • 452
  • 453
  • 454
  • 455
  • 456
  • 457
  • 458
  • 459
  • 460
  • 461
  • 462
  • 463
  • 464
  • 465
  • 466
  • 467
  • 468
  • 469
  • 470
  • 471
  • 472
  • 473
  • 474
  • 475
  • 476
  • 477
  • 478
  • 479
  • 480
  • 481
  • 482
  • 483
  • 484
  • 485
  • 486
  • 487
  • 488
  • 489
  • 490
  • 491
  • 492
  • 493
  • 494
  • 495
  • 496
  • 497
  • 498
  • 499
  • 500
  • 501
  • 502
  • 503
  • 504
  • 505
  • 506
  • 507
  • 508
  • 509
  • 510
  • 511
  • 512
  • 513
  • 514
  • 515
  • 516
  • 517
  • 518
  • 519
  • 520
  • 521
  • 522
  • 523
  • 524
  • 525
  • 526
  • 527
  • 528
  • 529
  • 530
  • 531
  • 532
  • 533
  • 534
  • 535
  • 536
  • 537
  • 538
  • 539
  • 540
  • 541
  • 542
  • 543
  • 544
  • 545

3.2. Services
3.2.1. Overview
A
Service
object is a reference to a specific IP protocol with associated parameters. A service
definition is usually based on one of the major transport protocols such as TCP or UDP which is
associated with a specific source and/or destination port number(s). For example, the
HTTP
service
is defined as using the TCP protocol with the associated destination port 80 and any source port.
However, service objects are not restricted to just the TCP or UDP protocols. They can be used to
encompass ICMP messages as well as a user-definable IP protocol.
A Service is Passive
Services are passive NetDefendOS objects in that they do not themselves carry out any action in the
configuration. Instead, service objects must be associated with the security policies defined by
various NetDefendOS rule sets and then act as a filter to apply those rules only to a specific type of
traffic.
For example, an IP rule in a NetDefendOS IP rule set has a service object associated with it as a
filtering parameter to decide whether or not to allow a specific type of traffic to traverse the
NetDefend Firewall. Inclusion in IP rules is one the most important usage of service objects and it is
also how ALGs become associated with IP rules since an ALG is associated with a service and not
directly with an IP rule.
For more information on how service objects are used with IP rules, see
Section 3.5, “IP Rule Sets”
.
Predefined Services
A large number of service objects are predefined in NetDefendOS. These include common services
such as
HTTP
,
FTP
,
Telnet
and
SSH
.
Predefined services can be used and also modified just like custom, user defined services. However,
it is recommended to
NOT
make any changes to predefined services and instead create custom
services with the desired characteristics.
Custom service creation in detail later in
Section 3.2.2, “Creating Custom Services”
.
Example 3.6. Listing the Available Services
To produce a listing of the available services in the system:
Command-Line Interface
gw-world:/>
show Service
The output will look similar to the following listing with the services grouped by type with the service groups
appearing first:
ServiceGroup
Name
Comments
------------ --------------------------------------------------
all_services All ICMP, TCP and UDP services
all_tcpudp
All TCP and UDP services
ipsec-suite
The IPsec+IKE suite
l2tp-ipsec
L2TP using IPsec for encryption and authentication
l2tp-raw
L2TP control and transport, unencrypted
pptp-suite
PPTP control and transport
ServiceICMP
3.2. Services
Chapter 3. Fundamentals
82