Chapter 24 IP Source Guard
XS3900-48F User’s Guide
209
24.5 DHCP Snooping Configure
Use this screen to enable DHCP snooping on the Switch (not on specific VLAN), specify the VLAN
where the default DHCP server is located, and configure the DHCP snooping database. The DHCP
snooping database stores the current bindings on a secure, external TFTP server so that they are
Last ignored bindings
counters
This section displays the number of times and the reasons the Switch ignored
bindings the last time it read bindings from the DHCP binding database. You can
clear these counters by restarting the Switch or using CLI commands. See the
Ethernet Switch CLI Reference Guide.
Binding collisions
This field displays the number of bindings the Switch ignored because the Switch
already had a binding with the same MAC address and VLAN ID.
Invalid interfaces
This field displays the number of bindings the Switch ignored because the port
number was a trusted interface or does not exist anymore.
Parse failures
This field displays the number of bindings the Switch ignored because the Switch
was unable to understand the binding in the DHCP binding database.
Expired leases
This field displays the number of bindings the Switch ignored because the lease
time had already expired.
Unsupported vlans
This field displays the number of bindings the Switch ignored because the VLAN ID
does not exist anymore.
Last ignored time
This field displays the last time the Switch ignored any bindings for any reason
from the DHCP binding database.
Total ignored bindings
counters
This section displays the reasons the Switch has ignored bindings any time it read
bindings from the DHCP binding database. You can clear these counters by
restarting the Switch or using CLI commands. See the Ethernet Switch CLI
Reference Guide.
Binding collisions
This field displays the number of bindings the Switch has ignored because the
Switch already had a binding with the same MAC address and VLAN ID.
Invalid interfaces
This field displays the number of bindings the Switch has ignored because the port
number was a trusted interface or does not exist anymore.
Parse failures
This field displays the number of bindings the Switch has ignored because the
Switch was unable to understand the binding in the DHCP binding database.
Expired leases
This field displays the number of bindings the Switch has ignored because the lease
time had already expired.
Unsupported vlans
This field displays the number of bindings the Switch has ignored because the VLAN
ID does not exist anymore.
Table 85
DHCP Snooping (continued)
LABEL
DESCRIPTION
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
