RHCA教程:rh442-1 利用snmp和mrtg监控linux服务器的网络流量

 

利用snmp和mrtg监控linux服务器的网络流量
一、环境
snmpd、mrtg服务器：station2.example.com： 192.168.32.32
      被监控客户端：station3.example.com：192.168.32.33
二、snmp服务器端安装和配置(station2)
1.      snmp安装
[root@station2 ~]# yum install net-snmp.i386
[root@station2 ~]#yuminstall net-snmp-devel.i386
[root@station2 ~]#yum install net-snmp-utils.i386
 
2.      snmp配置
[root@station2 ~]# snmptranslate -On SNMPv2-MIB::system
.1.3.6.1.2.1.1                  #参看system在mib中oid号
 
[root@station2 ~]#cp /etc/snmp/snmpd /etc/snmp/snmpd.orig 
#备份snmpd文件，默认情况下在运行snmpconf命令进行配置snmp是会覆盖此文件
[root@station2 ~]# snmpconf   
The following installed configuration files were found:
   1:  ./snmpd.conf
   2:  /etc/snmp/snmpd.conf
Would you like me to read them in?  Their content will be merged with the
output files created by this session.
Valid answer examples: "all", "none","3","1,2,5"
Read in which (default = all): 2     
 #读取/etc/snmp/snmpd.conf文件内容，并将其内容加入到新配置文件中
 
I can create the following types of configuration files for you.
Select the file type you wish to create:
(you can create more than one as you run this program)
   1:  snmpd.conf
   2:  snmptrapd.conf
   3:  snmp.conf
Other options: quit
Select File: 1    
#选择配置文件名，默认路径在/etc/snmp下，如果选择1会覆盖原配置文件
The configuration information which can be put into snmpd.conf is divided
into sections.  Select a configuration section for snmpd.conf
that you wish to create:
   1:  Trap Destinations
   2:  System Information Setup
   3:  Monitor Various Aspects of the Running Host
   4:  Extending the Agent
   5:  Access Control Setup
   6:  Agent Operating Mode
Other options: finished
Select section: 5     
#选择配置类型，5是访问配置，要通过snmp监控系统信息，得先配置访问控制
 
Section: Access Control Setup
Description:
  This section defines who is allowed to talk to your running
  snmp agent.
Select from:
   1:  a SNMPv3 read-write user
   2:  a SNMPv3 read-only user
   3:  a SNMPv1/SNMPv2c read-only access community name
   4:  a SNMPv1/SNMPv2c read-write access community name
Other options: finished, list
Select section: 3
#范围权限，选择3通过community（访问密码）进行只读访问
 
Configuring: rocommunity
Description:
  a SNMPv1/SNMPv2c read-only access community name
    arguments:  community [default|hostname|network/bits] [oid]
The community name to add read-only access for: example  
#example是community即访问密码
The hostname or network address to accept this community name from [RETURN for all]: 0.0.0.0/0                   #可访问得网段
The OID that this community should be restricted to [RETURN for no-restriction]:  #snmp监控类型，回车则表示监控所有信息。
Finished Output: rocommunity  example 0.0.0.0/0
Section: Access Control Setup
Description:
  This section defines who is allowed to talk to your running
  snmp agent.
Select from:
   1:  a SNMPv3 read-write user
   2:  a SNMPv3 read-only user
   3:  a SNMPv1/SNMPv2c read-only access community name
   4:  a SNMPv1/SNMPv2c read-write access community name
Other options: finished, list
Select section: finished                   #保存配置        
The configuration information which can be put into snmpd.conf is divided
into sections.  Select a configuration section for snmpd.conf
that you wish to create:
   1:  Trap Destinations
   2:  System Information Setup
   3:  Monitor Various Aspects of the Running Host
   4:  Extending the Agent
   5:  Access Control Setup
   6:  Agent Operating Mode
Other options: finished
Select section: finished
I can create the following types of configuration files for you.
Select the file type you wish to create:
(you can create more than one as you run this program)
   1:  snmpd.conf
   2:  snmptrapd.conf
   3:  snmp.conf
 
Other options: quit
Select File: quit
Error: An snmpd.conf file already exists in this directory.
'overwrite', 'skip', 'rename' or 'append'? : overwrite   #覆盖原配置文件
The following files were created:
  snmpd.conf 
These files should be moved to /usr/share/snmp if you
want them used by everyone on the system.  In the future, if you add
the -i option to the command line I'll copy them there automatically for you.
Or, if you want them for your personal use only, copy them to
/root/.snmp .  In the future, if you add the -p option to the
command line I'll copy them there automatically for you.
 
[root@station2 ~]# cp snmpd.conf /etc/snmp/snmpd.conf
cp：是否覆盖“/etc/snmp/snmpd.conf”? y   #将新配置文件覆盖原配置文件
 
[root@station2 ~]# cat /etc/snmp/snmpd.conf |grep example
#   example: pass .1.3.6.1.4.1.2021.255 /path/to/local/passtest
rocommunity  example 0.0.0.0/0
 
3.      启动snmpd服务
[root@station2 ~]# service snmpd start
启动 snmpd：                                               [确定]
 
[root@station2 ~]# chkconfig snmpd on
 
[root@station2 /]# snmpwalk -v1 -c example station2.example.com
#根据community为example查看stationa2.example的信息
SNMPv2-MIB::sysDescr.0 = STRING: Linux station2.example.com 2.6.18-194.el5 #1 SMP Tue Mar 16 21:52:43 EDT 2010 i686
SNMPv2-MIB::sysObjectID.0 = OID: NET-SNMP-MIB::netSnmpAgentOIDs.10
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (7433) 0:01:14.33
SNMPv2-MIB::sysContact.0 = STRING: Root  (configure /etc/snmp/snmp.local.conf)
SNMPv2-MIB::sysName.0 = STRING: station2.example.com
SNMPv2-MIB::sysLocation.0 = STRING: Unknown (edit /etc/snmp/snmpd.conf)
SNMPv2-MIB::sysORLastChange.0 = Timeticks: (1) 0:00:00.01
SNMPv2-MIB::sysORID.1 = OID: SNMPv2-MIB::snmpMIB
SNMPv2-MIB::sysORID.2 = OID: TCP-MIB::tcpMIB
SNMPv2-MIB::sysORID.3 = OID: IP-MIB::ip
SNMPv2-MIB::sysORID.4 = OID: UDP-MIB::udpMIB
SNMPv2-MIB::sysORID.5 = OID: SNMP-VIEW-BASED-ACM-MIB::vacmBasicGroup
SNMPv2-MIB::sysORID.6 = OID: SNMP-FRAMEWORK-MIB::snmpFrameworkMIBCompliance
SNMPv2-MIB::sysORID.7 = OID: SNMP-MPD-MIB::snmpMPDCompliance
SNMPv2-MIB::sysORID.8 = OID: SNMP-USER-BASED-SM-MIB::usmMIBCompliance
SNMPv2-MIB::sysORDescr.1 = STRING: The MIB module for SNMPv2 entities
SNMPv2-MIB::sysORDescr.2 = STRING: The MIB module for managing TCP implementations
SNMPv2-MIB::sysORDescr.3 = STRING: The MIB module for managing IP and ICMP implementations
。。。。。。
End of MIB

三、snmpd客户端口配置(station3)
1.      安装
[root@station2 ~]# yum install net-snmp.i386
2.      将stationa2的配置文件复制并覆盖station3的原配置文件
 [root@station3 ~]# scp 192.168.32.32:/etc/snmp/snmpd.conf /etc/snmp/snmpd.conf
[email protected]'s password:
snmpd.conf                                 100% 2771     2.7KB/s   00:00   
 
3.      启动snmpd代理服务
[root@station3 snmp]# service snmpd start
启动 snmpd：                                               [确定]
[root@station3 snmp]# chkconfig snmpd on
 
四、服务器端mrtg的安装和配置(station2)
1.      mrtg安装
[root@station2 ~]# yum install mrtg
#注在此默认httpd已经安装并配置，安装mrtg后会默认生成一个httpd配置文件/etc/httpd/conf.d/mrtg
 
2.      配置mrtg
[root@station2 /]# cfgmaker --ifref=name --global "workdir:/var/www/mrtg" [email protected] [email protected] >/etc/mrtg/mrtg.cfg
#根据snmpd的community定义mrtg的报表配置文件
 
[root@station2 /]# cat /etc/cron.d/mrtg  
*/5 * * * * root LANG=C LC_ALL=C /usr/bin/mrtg /etc/mrtg/mrtg.cfg --lock-file /var/lock/mrtg/mrtg_l --confcache-file /var/lib/mrtg/mrtg.ok
#该文件是安装mrtg时默认生成，表示每5分钟做一次数据读取
 
[root@station2 /]# LANG=C LC_ALL=C /usr/bin/mrtg /etc/mrtg/mrtg.cfg --lock-file /var/lock/mrtg/mrtg_l --confcache-file /var/lib/mrtg/mrtg.ok
#根据/etc/cron.d/mrtg中内容读取数据生成报表，要执行3次此命令才会不提示错误并成功。
 
[root@station2 /]# indexmaker /etc/mrtg/mrtg.cfg>/var/www/mrtg/index.html
#根据mrtg配置文件生成mrtg的默认首页
 
3.     配置httpd并测试
[root@station2 conf.d]# vi /etc/httpd/conf.d/mrtg.conf
Alias /mrtg /var/www/mrtg
    Order deny,allow
    Deny from all
    Allow from 0.0.0.0/0.0.0.0     #配置/var/www/mrtg的访问权限
[root@station2 conf.d]#servie httpd restart
通过IE访问http://192.168.32.32/mrtg