ZyXEL GS1920 Series User Guide - Page 283

DHCPv4 Status, DHCPv4 Relay

Page 283 highlights

Chapter 35 DHCP 35.3 DHCPv4 Status Click IP Application > DHCP > DHCPv4 in the navigation panel. The DHCP Status screen displays. Figure 206 IP Application > DHCP > DHCPv4 The following table describes the labels in this screen. Table 137 IP Application > DHCP > DHCPv4 LABEL Relay Status Relay Mode DESCRIPTION This section displays configuration settings related to the Switch's DHCP relay mode. This field displays: None - if the Switch is not configured as a DHCP relay agent. Global - if the Switch is configured as a DHCP relay agent only. VLAN - followed by a VLAN ID or multiple VLAN IDs if it is configured as a relay agent for specific VLAN(s). 35.4 DHCPv4 Relay Configure DHCP relay on the Switch if the DHCP clients and the DHCP server are not in the same broadcast domain. During the initial IP address leasing, the Switch helps to relay network information (such as the IP address and subnet mask) between a DHCP client and a DHCP server. Once the DHCP client obtains an IP address and can connect to the network, network information renewal is done between the DHCP client and the DHCP server without the help of the Switch. The Switch can be configured as a global DHCP relay. This means that the Switch forwards all DHCP requests from all domains to the same DHCP server. You can also configure the Switch to relay DHCP information based on the VLAN membership of the DHCP clients. 35.4.1 DHCPv4 Relay Agent Information The Switch can add information about the source of client DHCP requests that it relays to a DHCP server by adding Relay Agent Information. This helps provide authentication about the source of the requests. The DHCP server can then provide an IP address based on this information. Please refer to RFC 3046 for more details. The DHCP Relay Agent Information feature adds an Agent Information field (also known as the Option 82 field) to DHCP requests. The Option 82 field is in the DHCP headers of client DHCP request frames that the Switch relays to a DHCP server. GS1920 Series User's Guide 283

  • 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

Chapter 35 DHCP
GS1920 Series User’s Guide
283
35.3
DHCPv4 Status
Click
IP Application
>
DHCP > DHCPv4
in the navigation panel. The
DHCP Status
screen
displays.
Figure 206
IP Application > DHCP > DHCPv4
The following table describes the labels in this screen.
35.4
DHCPv4 Relay
Configure DHCP relay on the Switch if the DHCP clients and the DHCP server are not in the same
broadcast domain. During the initial IP address leasing, the Switch helps to relay network
information (such as the IP address and subnet mask) between a DHCP client and a DHCP server.
Once the DHCP client obtains an IP address and can connect to the network, network information
renewal is done between the DHCP client and the DHCP server without the help of the Switch.
The Switch can be configured as a global DHCP relay. This means that the Switch forwards all DHCP
requests from all domains to the same DHCP server. You can also configure the Switch to relay
DHCP information based on the VLAN membership of the DHCP clients.
35.4.1
DHCPv4 Relay Agent Information
The Switch can add information about the source of client DHCP requests that it relays to a DHCP
server by adding
Relay Agent Information
. This helps provide authentication about the source of
the requests. The DHCP server can then provide an IP address based on this information. Please
refer to RFC 3046 for more details.
The DHCP
Relay Agent Information
feature adds an Agent Information field (also known as the
Option 82
field) to DHCP requests. The
Option 82
field is in the DHCP headers of client DHCP
request frames that the Switch relays to a DHCP server.
Table 137
IP Application > DHCP > DHCPv4
LABEL
DESCRIPTION
Relay
Status
This section displays configuration settings related to the Switch’s DHCP relay mode.
Relay
Mode
This field displays:
None
- if the Switch is not configured as a DHCP relay agent.
Global
- if the Switch is configured as a DHCP relay agent only.
VLAN
- followed by a VLAN ID or multiple VLAN IDs if it is configured as a relay agent for specific
VLAN(s).