FREEBSD上安装snmp+mrtg还是比较简单的，如果你已经安装好了apache的话，看下面：
一：安装snmp：
以下%为SHELL提示符，且----线内为要添加或修改的部分，不要把----也写进去了。-_-!
安装snmp:
%cd /usr/ports/net-mgmt/net-snmp
%make install
修改/etc/rc.conf:
%ee /etc/rc.conf
加入：
------------------------------------------------------------------
snmpd_enable="YES"
snmpd_flags="-a -p /var/run/snmpd.pid"
snmptrapd_enable="YES"
snmptrapd_flags="-a -p /var/run/snmptrapd.pid"
------------------------------------------------------------------
运行下：
%/etc/netstart
编辑snmpd.conf：
%ee /usr/local/share/snmp/snmpd.conf
加入一行：
-------------------------------------------------------------
rocommunity public
#默认让snmp使用public用户
--------------------------------------------------------------
启动snmpd:
%/usr/local/etc/rc.d/snmpd.sh start
二：安装mrtg:
确定ports下的mrtg在什么位置：
%whereis mrtg
mrtg: /usr/ports/net-mgmt/mrtg
安装mrtg:
%cd /usr/ports/net-mgmt/mrtg
%make install
进入你apache的data目录（视个人情况而定，我的是/usr/local/www/apache22/data/wh-hisense/）：
%cd /usr/local/www/apache22/data/wh-hisense
在当前的WEB目录创建mrtg的目录：
%mkdir mrtg
三：配置mrtg：
进入mrtg的配置文件所在目录：
%cd /usr/local/etc/mrtg
用cfgmaker创建mrtg的配置文件：
%/usr/local/bin/cfgmaker public@mail.ahcbd.net > mrtg.cfg
记得将上面的mail.ahcbd.net换成你的主机名，
编辑mrtg.conf:
%ee mrtg.cfg
修改如下：
-----------------------------------------------------------------------------
LoadMIBs: /usr/local/share/snmp/mibs/UCD-SNMP-MIB.txt
WorkDir: /usr/local/www/apache22/data/wh-hisense/mrtg
Language: chinese
--------------------------------------------------------------------------------
并在文件尾加入：
-----------------------------------------------------------------------------------------------------
#Monitoring TCP connections
Target[tcpopen]: .1.3.6.1.2.1.6.9.0&.1.3.6.1.2.1.6.9.0:public@mail.ahcbd.net
Options[tcpopen]: nopercent,growright,gauge,noinfo
Title[tcpopen]: Open TCP connections
PageTop[tcpopen]: <h1>Open TCP connections</H1>
MaxBytes[tcpopen]: 1000000
YLegend[tcpopen]: # conns
ShortLegend[tcpopen]: connections
LegendI[tcpopen]:
Connections:
Legend1[tcpopen]: Open TCP connections
#monitoring User vs Idle CPU usage
Target[kontor.cpu]:ssCpuRawUser.0&ssCpuRawIdle.0:public@mail.ahcbd.net
RouterUptime[kontor.cpu]: public@mail.ahcbd.net
MaxBytes[kontor.cpu]: 100
Title[kontor.cpu]: CPU LOAD
PageTop[kontor.cpu]: <H1>User CPU Load %</H1>
Unscaled[kontor.cpu]: ymwd
ShortLegend[kontor.cpu]: %
YLegend[kontor.cpu]: CPU Utilization
Legend1[kontor.cpu]: User CPU in % (Load)
Legend2[kontor.cpu]: Idle CPU in % (Load)
LegendI[kontor.cpu]:
User
LegendO[kontor.cpu]:
Idle
Options[kontor.cpu]: growright,nopercent
#monitoring User vs System CPU usage
Target[kontor.usrsys]:ssCpuRawUser.0&ssCpuRawSystem.0:public@mail.ahcbd.net
RouterUptime[kontor.usrsys]: public@mail.ahcbd.net
MaxBytes[kontor.usrsys]: 100
Title[kontor.usrsys]: CPU LOAD
PageTop[kontor.usrsys]: <H1>CPU (user and system) Load %</H1>
Unscaled[kontor.usrsys]: ymwd
ShortLegend[kontor.usrsys]: %
YLegend[kontor.usrsys]: CPU Utilization
Legend1[kontor.usrsys]: User CPU in % (Load)
Legend2[kontor.usrsys]: System CPU in % (Load)
LegendI[kontor.usrsys]:
User
LegendO[kontor.usrsys]:
System
Options[kontor.usrsys]: growright,nopercent
#monitoring Active CPU usage
Target[kontor.cpusum]:ssCpuRawUser.0&ssCpuRawUser.0:public@mail.ahcbd.net +
ssCpuRawSystem.0&ssCpuRawSystem.0:public@mail.ahcbd.net
+ ssCpuRawNice.0&ssCpuRawNice.0:public@mail.ahcbd.net
RouterUptime[kontor.cpusum]: public@mail.ahcbd.net
MaxBytes[kontor.cpusum]: 100
Title[kontor.cpusum]: CPU LOAD
PageTop[kontor.cpusum]: <H1>Active CPU Load %</H1>
Unscaled[kontor.cpusum]: ymwd
ShortLegend[kontor.cpusum]: %
YLegend[kontor.cpusum]: CPU Utilization
Legend1[kontor.cpusum]: Active CPU in % (Load)
LegendI[kontor.cpusum]:
Active
Options[kontor.cpusum]: growright,nopercent
Target[freemem]: .1.3.6.1.4.1.2021.4.11.0&.1.3.6.1.4.1.2021.4.11.0:public@mail.ahcbd.net
Options[freemem]: nopercent,growright,gauge,noinfo
Title[freemem]: Free Memory
PageTop[freemem]: <h1>Free Memory</h1>
MaxBytes[freemem]: 1000000
kMG[freemem]: k,M,G,T,P,X
YLegend[freemem]: bytes
ShortLegend[freemem]: bytes
LegendI[freemem]:
Free Memory:
Legend1[freemem]: Free memory, not including swap, in bytes
--------------------------------------------------------------------------------------
记得将上面每处的mail.ahcbd.net换成你的主机名。且更改上面CPU，MEM等各部分的排列顺序等同于其在网页中的排列顺序
生成index.html文件：
/usr/local/bin/indexmaker –-title="监视页标题" --output=/home/http/mrtg/index.html mrtg.cfg
多运行几次:
/usr/local/bin/mrtg mrtg.cfg
直到没有出错提示为止
加入crontab每隔2分钟让数据刷新一次:
%ee /etc/crontab
------------------------------------------------------------------------
*/2 * * * * root /usr/local/bin/mrtg /usr/local/etc/mrtg/mrtg.cfg
--------------------------------------------------------------------
现在你可以用http://yourdomain.domain/mrtg/看到了。
End