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SNMPVACM(1)			    Net-SNMP			     SNMPVACM(1)

NAME
     snmpvacm  -  creates and maintains SNMPv3 View-based Access Control entries
     on a network entity

SYNOPSIS
     snmpvacm [COMMON OPTIONS] AGENT createSec2Group MODEL SECURITYNAME   GROUP-
     NAME
     snmpvacm [COMMON OPTIONS] AGENT deleteSec2Group MODEL SECURITYNAME
     snmpvacm [COMMON OPTIONS] AGENT createView [-Ce] NAME SUBTREE MASK
     snmpvacm [COMMON OPTIONS] AGENT deleteView NAME SUBTREE
     snmpvacm  [COMMON	OPTIONS]   AGENT  createAccess GROUPNAME [CONTEXTPREFIX]
     MODEL LEVEL CONTEXTMATCH READVIEW WRITEVIEW NOTIFYVIEW
     snmpvacm [COMMON OPTIONS]	 AGENT	deleteAccess  GROUPNAME  [CONTEXTPREFIX]
     MODEL LEVEL
     snmpvacm [COMMON OPTIONS]	AGENT createAuth GROUPNAME [CONTEXTPREFIX] MODEL
     LEVEL AUTHTYPE CONTEXTMATCH VIEW
     snmpvacm [COMMON OPTIONS]	AGENT deleteAuth GROUPNAME [CONTEXTPREFIX] MODEL
     LEVEL AUTHTYPE

DESCRIPTION
     snmpvacm  is  an SNMP application that can be used to do simple maintenance
     on the View-based Control Module (VACM) tables of an SNMP agent.	The  SN-
     MPv3  VACM  specifications  (see RFC2575) define assorted tables to specify
     groups of users, MIB views, and authorised access settings.  These snmpvacm
     commands effectively create or delete rows in the appropriate one of  these
     tables,  and match the equivalent configure directives which are documented
     in the snmpd.conf(5) man page.

     A fuller explanation of how these operate can be found in the project FAQ.

SUB-COMMANDS
   createSec2Group MODEL SECURITYNAME GROUPNAME
     Create an entry in the SNMPv3 security name to group table.  This table al-
     lows a single access control entry to be applied to a number of  users  (or
     'principals'),  and is indexed by the security model and security name val-
     ues.

     MODEL

	    An integer representing the security model, taking one of  the  fol-
	    lowing values:
	    1 - reserved for SNMPv1
	    2 - reserved for SNMPv2c
	    3 - User-based Security Model (USM)

     SECURITYNAME

	    A string representing the security name for a principal (represented
	    in	a  security-model-independent  format).  For USM-based requests,
	    the security name is the same as the username.

     GROUPNAME

	    A string identifying  the  group  that  this  entry  (i.e.	security
	    name/model	pair)  should  belong  to.  This group name will then be
	    referenced in the access table (see createAccess below).

   deleteSec2Group MODEL SECURITYNAME
     Delete an entry from the SNMPv3 security name to group table, thus removing
     access control settings for the given principal.  The entry to  be  removed
     is  indexed  by the MODEL and SECURITYNAME values, which should match those
     used in the corresponding createSec2Group command (or equivalent).

   createView [-Ce] NAME SUBTREE MASK
     Create an entry in the SNMPv3 MIB view table.  A MIB  view  consists  of  a
     family of view subtrees which may be individually included in or (occasion-
     ally)  excluded  from the view.  Each view subtree is defined by a combina-
     tion of an OID subtree together with a bit string mask.  The view table  is
     indexed by the view name and subtree OID values.

     [-Ce]

	    An	optional  flag	to indicate that this view subtree should be ex-
	    cluded from the named view.  If not specified, the default is to in-
	    clude the subtree in the view.  When constructing a view from a mix-
	    ture of included and excluded subtrees, the excluded subtrees should
	    be defined first - particularly if the named view is already  refer-
	    enced in one or more access entries.

     NAME

	    A  string  identifying a particular MIB view, of which this OID sub-
	    tree/mask forms part (possibly the only part).

     SUBTREE

	    The OID defining the root of the subtree to add to (or exclude from)
	    the named view.

     MASK

	    A bit mask indicating which sub-identifiers of the	associated  sub-
	    tree OID should be regarded as significant.

   deleteView NAME SUBTREE
     Delete  an entry from the SNMPv3 view table, thus removing the subtree from
     the given MIB view.  Removing the final (or only) subtree	will  result  in
     the  deletion  of the view.  The entry to be removed is indexed by the NAME
     and SUBTREE values, which should match those used in the corresponding cre-
     ateView command (or equivalent).

     When removing subtrees from a mixed view (i.e. containing both included and
     excluded subtrees), the included subtrees should be removed first.

   createAccess GROUPNAME  [CONTEXTPREFIX]  MODEL  LEVEL  CONTEXTMATCH	READVIEW
     WRITEVIEW NOTIFYVIEW
     Create  an  entry in the SNMPv3 access table, thus allowing a certain level
     of access to particular MIB views for the principals in the specified group
     (given suitable security model and levels in the request).  The access  ta-
     ble  is indexed by the group name, context prefix, security model and secu-
     rity level values.

     GROUPNAME

	    The name of the group that this access entry applies to (as  set  up
	    by a createSec2Group command, or equivalent)

     CONTEXTPREFIX

	    A  string  representing  a	context  name  (or collection of context
	    names) which this access entry applies to.	 The  interpretation  of
	    this  string depends on the value of the CONTEXTMATCH field (see be-
	    low).

	    If omitted, this will default to the null context "".

     MODEL

	    An integer representing the security model, taking one of  the  fol-
	    lowing values:
	    1 - reserved for SNMPv1
	    2 - reserved for SNMPv2c
	    3 - User-based Security Model (USM)

     LEVEL

	    An	integer  representing  the minimal security level, taking one of
	    the following values:
	    1 - noAuthNoPriv
	    2 - authNoPriv
	    3 - authPriv

	    This access entry will be applied  to  requests  of  this  level  or
	    higher  (where  authPriv  is higher than authNoPriv which is in turn
	    higher than noAuthNoPriv).

     CONTEXTMATCH

	    Indicates how to interpret the CONTEXTPREFIX value.  If  this  field
	    has  the value '1' (representing 'exact') then the context name of a
	    request must match the CONTEXTPREFIX value exactly for  this  access
	    entry to be applicable to that request.

	    If	this  field  has  the value '2' (representing 'prefix') then the
	    initial substring of the context name of a request	must  match  the
	    CONTEXTPREFIX  value  for this access entry to be applicable to that
	    request.  This provides a simple form of wildcarding.

     READVIEW

	    The name of the MIB view (as set up  by  createView  or  equivalent)
	    defining the MIB objects for which this request may request the cur-
	    rent values.

	    If there is no view with this name, then read access is not granted.

     WRITEVIEW

	    The  name  of  the	MIB view (as set up by createView or equivalent)
	    defining the MIB objects for which this request may potentially  SET
	    new values.

	    If there is no view with this name, then read access is not granted.

     NOTIFYVIEW

	    The  name  of  the	MIB view (as set up by createView or equivalent)
	    defining the MIB objects which may be included in  notification  re-
	    quest.

	    Note that this aspect of access control is not currently supported.

   deleteAccess GROUPNAME [CONTEXTPREFIX] MODEL LEVEL
     Delete  an  entry from the SNMPv3 access table, thus removing the specified
     access control settings.  The entry to be removed is indexed by  the  group
     name,  context  prefix,  security	model  and  security level values, which
     should match those used  in  the  corresponding  createAccess  command  (or
     equivalent).

   createAuth GROUPNAME [CONTEXTPREFIX] MODEL LEVEL AUTHTYPE CONTEXTMATCH VIEW
     Create  an  entry	in  the Net-SNMP extension to the standard access table,
     thus allowing a certain type of access to the MIB view for  the  principals
     in  the  specified  group.  The interpretation of GROUPNAME, CONTEXTPREFIX,
     MODEL, LEVEL and CONTEXTMATCH are the same as for the  createAccess  direc-
     tive.   The  extension  access  table is indexed by the group name, context
     prefix, security model, security level and authtype values.

     AUTHTYPE

	    The style of access that this entry should be applied to.	See  sn-
	    mpd.conf(5) and snmptrapd.conf(5) for details of valid tokens.

     VIEW

	    The  name  of  the	MIB view (as set up by createView or equivalent)
	    defining the MIB objects for which this style of  access  is  autho-
	    rized.

   deleteAuth GROUPNAME [CONTEXTPREFIX] MODEL LEVEL AUTHTYPE
     Delete  an  entry from the extension access table, thus removing the speci-
     fied access control settings.  The entry to be removed is	indexed  by  the
     group  name,  context  prefix,  security model, security level and authtype
     values, which should match those used in the corresponding createAuth  com-
     mand (or equivalent).

     Note  that  snmpget  REQUIRES  an argument specifying the agent to query as
     described in the .I snmpcmd(1) manual page.

EXAMPLES
     Given a pre-existing user dave (which could be set up using the  snmpusm(1)
     command),	we  could configure full read-write access to the whole OID tree
     using the commands:

	    snmpvacm localhost createSec2Group 3 dave RWGroup

	    snmpvacm localhost createView   all .1 80

	    snmpvacm localhost createAccess  RWGroup 3 1 1 all all none

     This creates a new security group named  "RWGroup"  containing  the  SNMPv3
     user "dave", a new view "all" containing the full OID tree based on .iso(1)
     ,	and  then  allows  those users in the group "RWGroup" (i.e. "dave") both
     read- and write-access to the view "all" (i.e. the full OID tree) when  us-
     ing authenticated SNMPv3 requests.

     As  a  second example, we could set up read-only access to a portion of the
     OID tree using the commands:

	    snmpvacm localhost createSec2Group 3 wes ROGroup

	    snmpvacm localhost createView   sysView  system fe

	    snmpvacm localhost createAccess  ROGroup 3 0 1 sysView none none

     This creates a new security group named "ROGroup" containing  the	(pre-ex-
     isting) user "wes", a new view "sysView" containing just the OID tree based
     on  .iso(1).org(3).dod(6).inet(1).mgmt(2).mib-2(1).system(1) , and then al-
     lows those users in the group "ROGroup" (i.e. "wes") read-access,	but  not
     write-access to the view "sysView" (i.e. the system group).

EXIT STATUS
     The following exit values are returned:

     0 - Successful completion

     1 - A usage syntax error (which displays a suitable usage message) or a re-
     quest timeout.

     2	-  An  error occurred while executing the command (which also displays a
     suitable error message).

LIMITATIONS
     This utility does not support the configuration of new  community	strings,
     so  is  only  of use for setting up new access control for SNMPv3 requests.
     It can be used to amend the access settings for existing community strings,
     but not to set up new ones.

     The use of numeric parameters for secLevel and contextMatch  parameters  is
     less than intuitive.  These commands do not provide the full flexibility of
     the equivalent config file directives.

     There  is	(currently)  no  equivalent to the one-shot configure directives
     rouser and rwuser.

SEE ALSO
     snmpcmd(1), snmpusm(1), snmpd.conf(5),  snmp.conf(5),  RFC  2575,	Net-SNMP
     project FAQ

V5.9.5.2			   05 Sep 2006			     SNMPVACM(1)

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