ubuntu-16.04net-snmpsnmpd

snmpget : Unknown user name


I am trying to install net-snmp from scratch to make snmpv3 to work on my computer.

I did install net-snmp and create the user, but when I want to make snmpget it reject me with snmpget: Unknown user name


###############################################################################
#
# EXAMPLE.conf:
#   An example configuration file for configuring the Net-SNMP agent ('snmpd')
#   See the 'snmpd.conf(5)' man page for details
#
#  Some entries are deliberately commented out, and will need to be explicitly activated
#
###############################################################################
#
#  AGENT BEHAVIOUR
#

#  Listen for connections from the local system only
# agentAddress  udp:127.0.0.1:161
#  Listen for connections on all interfaces (both IPv4 *and* IPv6)
agentAddress udp:161,udp6:[::1]:161



###############################################################################
#
#  SNMPv3 AUTHENTICATION
#
#  Note that these particular settings don't actually belong here.
#  They should be copied to the file /var/lib/snmp/snmpd.conf
#     and the passwords changed, before being uncommented in that file *only*.
#  Then restart the agent

#  createUser authOnlyUser  MD5 "remember to change this password"
#  createUser authPrivUser  SHA "remember to change this one too"  DES
#  createUser internalUser  MD5 "this is only ever used internally, but still change the password"

#  If you also change the usernames (which might be sensible),
#  then remember to update the other occurances in this example config file to match.



###############################################################################
#
#  ACCESS CONTROL
#

                                                 #  system + hrSystem groups only
view   systemonly  included   .1.3.6.1.2.1.1
view   systemonly  included   .1.3.6.1.2.1.25.1

                                                 #  Full access from the local host
#rocommunity public  localhost
                                                 #  Default access to basic system info
 rocommunity public  default    -V systemonly
                                                 #  rocommunity6 is for IPv6
 rocommunity6 public  default   -V systemonly

                                                 #  Full access from an example network
                                                 #     Adjust this network address to match your local
                                                 #     settings, change the community string,
                                                 #     and check the 'agentAddress' setting above
#rocommunity secret  10.0.0.0/16

                                                 #  Full read-only access for SNMPv3
 rouser   authOnlyUser
                                                 #  Full write access for encrypted requests
                                                 #     Remember to activate the 'createUser' lines above
#rwuser   authPrivUser   priv

#  It's no longer typically necessary to use the full 'com2sec/group/access' configuration
#  r[ow]user and r[ow]community, together with suitable views, should cover most requirements



###############################################################################
#
#  SYSTEM INFORMATION
#

#  Note that setting these values here, results in the corresponding MIB objects being 'read-only'
#  See snmpd.conf(5) for more details
sysLocation    Sitting on the Dock of the Bay
sysContact     Me <me@example.org>
                                                 # Application + End-to-End layers
sysServices    72


#
#  Process Monitoring
#
                               # At least one  'mountd' process
proc  mountd
                               # No more than 4 'ntalkd' processes - 0 is OK
proc  ntalkd    4
                               # At least one 'sendmail' process, but no more than 10
proc  sendmail 10 1

#  Walk the UCD-SNMP-MIB::prTable to see the resulting output
#  Note that this table will be empty if there are no "proc" entries in the snmpd.conf file


#
#  Disk Monitoring
#
                               # 10MBs required on root disk, 5% free on /var, 10% free on all other disks
disk       /     10000
disk       /var  5%
includeAllDisks  10%

#  Walk the UCD-SNMP-MIB::dskTable to see the resulting output
#  Note that this table will be empty if there are no "disk" entries in the snmpd.conf file


#
#  System Load
#
                               # Unacceptable 1-, 5-, and 15-minute load averages
load   12 10 5

#  Walk the UCD-SNMP-MIB::laTable to see the resulting output
#  Note that this table *will* be populated, even without a "load" entry in the snmpd.conf file



###############################################################################
#
#  ACTIVE MONITORING
#

                                    #   send SNMPv1  traps
 trapsink     localhost public
                                    #   send SNMPv2c traps
#trap2sink    localhost public
                                    #   send SNMPv2c INFORMs
#informsink   localhost public

#  Note that you typically only want *one* of these three lines
#  Uncommenting two (or all three) will result in multiple copies of each notification.


#
#  Event MIB - automatically generate alerts
#
                                   # Remember to activate the 'createUser' lines above
iquerySecName   internalUser       
rouser          internalUser
                                   # generate traps on UCD error conditions
defaultMonitors          yes
                                   # generate traps on linkUp/Down
linkUpDownNotifications  yes



###############################################################################
#
#  EXTENDING THE AGENT
#

#
#  Arbitrary extension commands
#
 extend    test1   /bin/echo  Hello, world!
 extend-sh test2   echo Hello, world! ; echo Hi there ; exit 35
#extend-sh test3   /bin/sh /tmp/shtest

#  Note that this last entry requires the script '/tmp/shtest' to be created first,
#    containing the same three shell commands, before the line is uncommented

#  Walk the NET-SNMP-EXTEND-MIB tables (nsExtendConfigTable, nsExtendOutput1Table
#     and nsExtendOutput2Table) to see the resulting output

#  Note that the "extend" directive supercedes the previous "exec" and "sh" directives
#  However, walking the UCD-SNMP-MIB::extTable should still returns the same output,
#     as well as the fuller results in the above tables.


#
#  "Pass-through" MIB extension command
#
#pass .1.3.6.1.4.1.8072.2.255  /bin/sh       PREFIX/local/passtest
#pass .1.3.6.1.4.1.8072.2.255  /usr/bin/perl PREFIX/local/passtest.pl

# Note that this requires one of the two 'passtest' scripts to be installed first,
#    before the appropriate line is uncommented.
# These scripts can be found in the 'local' directory of the source distribution,
#     and are not installed automatically.

#  Walk the NET-SNMP-PASS-MIB::netSnmpPassExamples subtree to see the resulting output


#
#  AgentX Sub-agents
#
                                           #  Run as an AgentX master agent
 master          agentx
                                           #  Listen for network connections (from localhost)
                                           #    rather than the default named socket /var/agentx/master
#agentXSocket    tcp:localhost:705

rouser neutg


createUser neutg SHA "password" AES passphrase

The command I run is :

snmpget -u neutg -A password -a SHA -X 'passphrase' 
        -x AES -l authPriv localhost -v 3 1.3.6.1.2.1.1

enter image description here


I don't understand why it do not take in count my user. (I did restart the snmpd after entering the user - multiple times!)

enter image description here


The version of net-snmp I use :

enter image description here

Thanks in advance :)


Solution

  • After many research I've found what the problem is.

    snmpd was not taking in count my configuration files. I saw it using the command :

    snmpd -Dread_config -H 2>&1 | grep "Reading" | sort -u 
    

    Which tells you which configurations files are loaded by snmpd.


    You can see it as well looking at the configuration file /var/lib/snmp/snmpd.conf. When snmpd handle your users it creates special lines in the file. It looks like :

    usmUser 1 3 0x80001f888074336938f74f7c5a00000000 "neutg" "neutg" NULL .1.3.6.1.6.3.10.1.1.3 0xf965e4ab0f35eebb3f0e3b30\
    6bc0797c025821c5 .1.3.6.1.6.3.10.1.2.4 0xe277044beccd9991d70144c4c8f4b672 0x
    usmUser 1 3 0x80001f888074336938f74f7c5a00000000 "myuser" "myuser" NULL .1.3.6.1.6.3.10.1.1.2 0x2223c2d00758353b7c3076\
    236be02152 .1.3.6.1.6.3.10.1.2.2 0x2223c2d00758353b7c3076236be02152 0x
    setserialno 1424757026
    

    So if you do not see any usmUser it's probably that your badly added your users.


    The soluce

     sudo /usr/local/sbin/snmpd -c /var/net-snmp/snmpd.conf -c /usr/local/share/snmp/snmpd.conf