1SNMPVACM(1) Net-SNMP SNMPVACM(1)
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6 snmpvacm - creates and maintains SNMPv3 View-based Access Control en‐
7 tries on a network entity
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10 snmpvacm [COMMON OPTIONS] AGENT createSec2Group MODEL SECURITYNAME
11 GROUPNAME
12 snmpvacm [COMMON OPTIONS] AGENT deleteSec2Group MODEL SECURITYNAME
13 snmpvacm [COMMON OPTIONS] AGENT createView [-Ce] NAME SUBTREE MASK
14 snmpvacm [COMMON OPTIONS] AGENT deleteView NAME SUBTREE
15 snmpvacm [COMMON OPTIONS] AGENT createAccess GROUPNAME [CONTEXTPREFIX]
16 MODEL LEVEL CONTEXTMATCH READVIEW WRITEVIEW NOTIFYVIEW
17 snmpvacm [COMMON OPTIONS] AGENT deleteAccess GROUPNAME [CONTEXTPREFIX]
18 MODEL LEVEL
19 snmpvacm [COMMON OPTIONS] AGENT createAuth GROUPNAME [CONTEXTPREFIX]
20 MODEL LEVEL AUTHTYPE CONTEXTMATCH VIEW
21 snmpvacm [COMMON OPTIONS] AGENT deleteAuth GROUPNAME [CONTEXTPREFIX]
22 MODEL LEVEL AUTHTYPE
23
26 snmpvacm is an SNMP application that can be used to do simple mainte‐
27 nance on the View-based Control Module (VACM) tables of an SNMP agent.
28 The SNMPv3 VACM specifications (see RFC2575) define assorted tables to
29 specify groups of users, MIB views, and authorised access settings.
30 These snmpvacm commands effectively create or delete rows in the appro‐
31 priate one of these tables, and match the equivalent configure direc‐
32 tives which are documented in the snmpd.conf(5) man page.
33 A fuller explanation of how these operate can be found in the project
35 FAQ.
36
38 createSec2Group MODEL SECURITYNAME GROUPNAME
39 Create an entry in the SNMPv3 security name to group table. This table
40 allows a single access control entry to be applied to a number of users
41 (or 'principals'), and is indexed by the security model and security
42 name values.
43 MODEL
45 An integer representing the security model, taking one of the
47 following values:
48 1 - reserved for SNMPv1
49 2 - reserved for SNMPv2c
50 3 - User-based Security Model (USM)
51 SECURITYNAME
54 A string representing the security name for a principal (repre‐
56 sented in a security-model-independent format). For USM-based
57 requests, the security name is the same as the username.
58 GROUPNAME
61 A string identifying the group that this entry (i.e. security
63 name/model pair) should belong to. This group name will then be
64 referenced in the access table (see createAccess below).
65 deleteSec2Group MODEL SECURITYNAME
67 Delete an entry from the SNMPv3 security name to group table, thus re‐
68 moving access control settings for the given principal. The entry to
69 be removed is indexed by the MODEL and SECURITYNAME values, which
70 should match those used in the corresponding createSec2Group command
71 (or equivalent).
72 createView [-Ce] NAME SUBTREE MASK
75 Create an entry in the SNMPv3 MIB view table. A MIB view consists of a
76 family of view subtrees which may be individually included in or (occa‐
77 sionally) excluded from the view. Each view subtree is defined by a
78 combination of an OID subtree together with a bit string mask. The
79 view table is indexed by the view name and subtree OID values.
80 [-Ce]
82 An optional flag to indicate that this view subtree should be
84 excluded from the named view. If not specified, the default is
85 to include the subtree in the view. When constructing a view
86 from a mixture of included and excluded subtrees, the excluded
87 subtrees should be defined first - particularly if the named
88 view is already referenced in one or more access entries.
89 NAME
91 A string identifying a particular MIB view, of which this OID
93 subtree/mask forms part (possibly the only part).
94 SUBTREE
96 The OID defining the root of the subtree to add to (or exclude
98 from) the named view.
99 MASK
101 A bit mask indicating which sub-identifiers of the associated
103 subtree OID should be regarded as significant.
104 deleteView NAME SUBTREE
107 Delete an entry from the SNMPv3 view table, thus removing the subtree
108 from the given MIB view. Removing the final (or only) subtree will re‐
109 sult in the deletion of the view. The entry to be removed is indexed
110 by the NAME and SUBTREE values, which should match those used in the
111 corresponding createView command (or equivalent).
112 When removing subtrees from a mixed view (i.e. containing both included
114 and excluded subtrees), the included subtrees should be removed first.
115 createAccess GROUPNAME [CONTEXTPREFIX] MODEL LEVEL CONTEXTMATCH READVIEW
118 WRITEVIEW NOTIFYVIEW
119 Create an entry in the SNMPv3 access table, thus allowing a certain
120 level of access to particular MIB views for the principals in the spec‐
121 ified group (given suitable security model and levels in the request).
122 The access table is indexed by the group name, context prefix, security
123 model and security level values.
124 GROUPNAME
126 The name of the group that this access entry applies to (as set
128 up by a createSec2Group command, or equivalent)
129 CONTEXTPREFIX
131 A string representing a context name (or collection of context
133 names) which this access entry applies to. The interpretation
134 of this string depends on the value of the CONTEXTMATCH field
135 (see below).
136 If omitted, this will default to the null context "".
138 MODEL
140 An integer representing the security model, taking one of the
142 following values:
143 1 - reserved for SNMPv1
144 2 - reserved for SNMPv2c
145 3 - User-based Security Model (USM)
146 LEVEL
148 An integer representing the minimal security level, taking one
150 of the following values:
151 1 - noAuthNoPriv
152 2 - authNoPriv
153 3 - authPriv
154 This access entry will be applied to requests of this level or
156 higher (where authPriv is higher than authNoPriv which is in
157 turn higher than noAuthNoPriv).
158 CONTEXTMATCH
160 Indicates how to interpret the CONTEXTPREFIX value. If this
162 field has the value '1' (representing 'exact') then the context
163 name of a request must match the CONTEXTPREFIX value exactly for
164 this access entry to be applicable to that request.
165 If this field has the value '2' (representing 'prefix') then the
167 initial substring of the context name of a request must match
168 the CONTEXTPREFIX value for this access entry to be applicable
169 to that request. This provides a simple form of wildcarding.
170 READVIEW
172 The name of the MIB view (as set up by createView or equivalent)
174 defining the MIB objects for which this request may request the
175 current values.
176 If there is no view with this name, then read access is not
178 granted.
179 WRITEVIEW
181 The name of the MIB view (as set up by createView or equivalent)
183 defining the MIB objects for which this request may potentially
184 SET new values.
185 If there is no view with this name, then read access is not
187 granted.
188 NOTIFYVIEW
190 The name of the MIB view (as set up by createView or equivalent)
192 defining the MIB objects which may be included in notification
193 request.
194 Note that this aspect of access control is not currently sup‐
196 ported.
197 deleteAccess GROUPNAME [CONTEXTPREFIX] MODEL LEVEL
200 Delete an entry from the SNMPv3 access table, thus removing the speci‐
201 fied access control settings. The entry to be removed is indexed by
202 the group name, context prefix, security model and security level val‐
203 ues, which should match those used in the corresponding createAccess
204 command (or equivalent).
205 createAuth GROUPNAME [CONTEXTPREFIX] MODEL LEVEL AUTHTYPE CONTEXTMATCH VIEW
208 Create an entry in the Net-SNMP extension to the standard access table,
209 thus allowing a certain type of access to the MIB view for the princi‐
210 pals in the specified group. The interpretation of GROUPNAME, CON‐
211 TEXTPREFIX, MODEL, LEVEL and CONTEXTMATCH are the same as for the cre‐
212 ateAccess directive. The extension access table is indexed by the
213 group name, context prefix, security model, security level and authtype
214 values.
215 AUTHTYPE
217 The style of access that this entry should be applied to. See
219 snmpd.conf(5) and snmptrapd.conf(5) for details of valid tokens.
220 VIEW
222 The name of the MIB view (as set up by createView or equivalent)
224 defining the MIB objects for which this style of access is au‐
225 thorized.
226 deleteAuth GROUPNAME [CONTEXTPREFIX] MODEL LEVEL AUTHTYPE
229 Delete an entry from the extension access table, thus removing the
230 specified access control settings. The entry to be removed is indexed
231 by the group name, context prefix, security model, security level and
232 authtype values, which should match those used in the corresponding
233 createAuth command (or equivalent).
234 Note that snmpget REQUIRES an argument specifying the agent to query
237 as described in the .I snmpcmd(1) manual page.
238
241 Given a pre-existing user dave (which could be set up using the snm‐
242 pusm(1) command), we could configure full read-write access to the
243 whole OID tree using the commands:
244 snmpvacm localhost createSec2Group 3 dave RWGroup
247 snmpvacm localhost createView all .1 80
249 snmpvacm localhost createAccess RWGroup 3 1 1 all all none
251 This creates a new security group named "RWGroup" containing the SNMPv3
253 user "dave", a new view "all" containing the full OID tree based on
254 .iso(1) , and then allows those users in the group "RWGroup" (i.e.
255 "dave") both read- and write-access to the view "all" (i.e. the full
256 OID tree) when using authenticated SNMPv3 requests.
257 As a second example, we could set up read-only access to a portion of
260 the OID tree using the commands:
261 snmpvacm localhost createSec2Group 3 wes ROGroup
264 snmpvacm localhost createView sysView system fe
266 snmpvacm localhost createAccess ROGroup 3 0 1 sysView none none
268 This creates a new security group named "ROGroup" containing the (pre-
270 existing) user "wes", a new view "sysView" containing just the OID tree
271 based on .iso(1).org(3).dod(6).inet(1).mgmt(2).mib-2(1).system(1) , and
272 then allows those users in the group "ROGroup" (i.e. "wes") read-ac‐
273 cess, but not write-access to the view "sysView" (i.e. the system
274 group).
275
278 The following exit values are returned:
279 0 - Successful completion
281 1 - A usage syntax error (which displays a suitable usage message) or a
283 request timeout.
284 2 - An error occurred while executing the command (which also displays
286 a suitable error message).
287
290 This utility does not support the configuration of new community
291 strings, so is only of use for setting up new access control for SNMPv3
292 requests. It can be used to amend the access settings for existing
293 community strings, but not to set up new ones.
294 The use of numeric parameters for secLevel and contextMatch parameters
297 is less than intuitive. These commands do not provide the full flexi‐
298 bility of the equivalent config file directives.
299 There is (currently) no equivalent to the one-shot configure directives
302 rouser and rwuser.
303
306 snmpcmd(1), snmpusm(1), snmpd.conf(5), snmp.conf(5), RFC 2575, Net-SNMP
307 project FAQ
308V5.9.1 05 Sep 2006 SNMPVACM(1)