我是否需要启用一些标志，以便使用SNMP监视Ubuntu？

Question

斯内普跑了。我通过运行snmpwalk(snmpwalk -v 1 -c public localhost)来检查状态。

我运行这个是为了获取CPU信息：

snmpget -v 1 -c "community" localhost .1.3.6.1.4.1.2021.10.1.3.1

但我发现了一个错误：

Timeout: No Response from localhost

我是否需要启用一些东西来启用SNMP监视？

snmpd.conf：

###############################################################################
#
# 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

                                                 #  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[ou]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

Answer 1

您需要确保"localhost“可以使用该社区字符串”community“。而且，在您的snmpd.conf文件中，您根本没有定义社区字符串" community“。

对于初始测试，添加rwcommunity community localhost作为"/etc/snmp/snmpd.conf“中的第一行并重新启动服务。

这应该允许您只从本地主机执行SNMP操作。

如果希望能够从其他地方读取SNMP数据，只需将"localhost“更改为要连接的服务器的IP地址或主机名。在生产环境中，您可能希望通过使SNMP只读、使用更模糊的社区字符串或使用v2c/v3安全定义来使SNMP更安全。不过，这应该会让你开始测试。

Answer 2

如果snmpd只在127.0.0.1或在实际网络接口上侦听，请参阅/etc/default/snmpd。看看那里的SNMPDOPTS线。