CentOS下面安装SNMP协议
检查是否安装snmp服务
# rpm -qa |grep snmp
yum安装
yum install -y net-snmp
yum install -y net-snmp-devel
yum install -y net-snmp-libs
yum install -y net-snmp-perl
yum install -y net-snmp-utils
yum install -y mrtg
启动服务
service snmpd start
service snmpd status
service snmpd restart
配置snmp
配置文件存放在：/etc/snmp/目录下面的snmpd.conf文件
41行
# sec.name source community
# 增加配置用户名(sec.name)，允许访问的IP(source)，服务团体(community)，团体就是类似于密钥的意思。用户在访问的时候必须使用正确的团体名才能正常访问
com2sec notConfigUser localhost public
com2sec notConfigUser 192.168.20.186 public
com2sec notConfigUser 192.168.10.11 public
58行
# name incl/excl subtree mask(optional)
#增加用户的访问程序权限，all
view all included .1 80
66行
# group context sec.model sec.level prefix read write notif
# 增加用户组的读写权限
access notConfigGroup "" any noauth exact all none none
验证服务可用性
[root@localhost snmp]# snmpwalk -v 1 192.168.20.186 -c public system
SNMPv2-MIB::sysDescr.0 = STRING: Linux localhost.localdomain 3.10.0-693.el7.x86_64 #1 SMP Tue Aug 22 21:09:27 UTC 2017 x86_64
SNMPv2-MIB::sysObjectID.0 = OID: NET-SNMP-MIB::netSnmpAgentOIDs.10
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (915186) 2:32:31.86
SNMPv2-MIB::sysContact.0 = STRING: Root
SNMPv2-MIB::sysName.0 = STRING: localhost.localdomain
SNMPv2-MIB::sysLocation.0 = STRING: Unknown (edit /etc/snmp/snmpd.conf)
SNMPv2-MIB::sysORLastChange.0 = Timeticks: (0) 0:00:00.00
SNMPv2-MIB::sysORID.1 = OID: SNMP-MPD-MIB::snmpMPDCompliance
SNMPv2-MIB::sysORID.2 = OID: SNMP-USER-BASED-SM-MIB::usmMIBCompliance
SNMPv2-MIB::sysORID.3 = OID: SNMP-FRAMEWORK-MIB::snmpFrameworkMIBCompliance
SNMPv2-MIB::sysORID.4 = OID: SNMPv2-MIB::snmpMIB
SNMPv2-MIB::sysORID.5 = OID: TCP-MIB::tcpMIB
SNMPv2-MIB::sysORID.6 = OID: IP-MIB::ip
SNMPv2-MIB::sysORID.7 = OID: UDP-MIB::udpMIB
SNMPv2-MIB::sysORID.8 = OID: SNMP-VIEW-BASED-ACM-MIB::vacmBasicGroup
SNMPv2-MIB::sysORID.9 = OID: SNMP-NOTIFICATION-MIB::snmpNotifyFullCompliance
SNMPv2-MIB::sysORID.10 = OID: NOTIFICATION-LOG-MIB::notificationLogMIB
SNMPv2-MIB::sysORDescr.1 = STRING: The MIB for Message Processing and Dispatching.
SNMPv2-MIB::sysORDescr.2 = STRING: The management information definitions for the SNMP User-based Security Model.
SNMPv2-MIB::sysORDescr.3 = STRING: The SNMP Management Architecture MIB.
SNMPv2-MIB::sysORDescr.4 = STRING: The MIB module for SNMPv2 entities
SNMPv2-MIB::sysORDescr.5 = STRING: The MIB module for managing TCP implementations
SNMPv2-MIB::sysORDescr.6 = STRING: The MIB module for managing IP and ICMP implementations
SNMPv2-MIB::sysORDescr.7 = STRING: The MIB module for managing UDP implementations
SNMPv2-MIB::sysORDescr.8 = STRING: View-based Access Control Model for SNMP.
SNMPv2-MIB::sysORDescr.9 = STRING: The MIB modules for managing SNMP Notification, plus filtering.
SNMPv2-MIB::sysORDescr.10 = STRING: The MIB module for logging SNMP Notifications.
SNMPv2-MIB::sysORUpTime.1 = Timeticks: (0) 0:00:00.00
SNMPv2-MIB::sysORUpTime.2 = Timeticks: (0) 0:00:00.00
SNMPv2-MIB::sysORUpTime.3 = Timeticks: (0) 0:00:00.00
SNMPv2-MIB::sysORUpTime.4 = Timeticks: (0) 0:00:00.00
SNMPv2-MIB::sysORUpTime.5 = Timeticks: (0) 0:00:00.00
SNMPv2-MIB::sysORUpTime.6 = Timeticks: (0) 0:00:00.00
SNMPv2-MIB::sysORUpTime.7 = Timeticks: (0) 0:00:00.00
SNMPv2-MIB::sysORUpTime.8 = Timeticks: (0) 0:00:00.00
SNMPv2-MIB::sysORUpTime.9 = Timeticks: (0) 0:00:00.00
防火墙配置
确保udp 161端口可以正常开启，并被访问
编写自定义脚本获取相应的状态
Memory 脚本：
#!/bin/sh
/usr/bin/free -m | grep Mem |awk '{print $4}'
/usr/bin/free -m | grep Mem |awk '{print $2}'
[root@localhost snmp]# sh memory.sh
809
1006
CPU 脚本：
#!/bin/sh
idle=`sar -u 1 3 | grep Average | awk '{print $6}'`
used=`echo "101 - $idle" | bc -l -s`
echo $used
echo $idle
Disk I/O 脚本：
#!/bin/sh
used1=`sar -d 1 3 | tail -1 | awk '{print $4}'`
used2=`echo "$used1 / 2" | bc -l`
echo $used2
echo $used2
在/etc/snmp/snmpd.conf中增加配置项
exec .1.3.6.1.4.1.2021.53 memory /bin/sh /root/memory.sh
exec .1.3.6.1.4.1.2021.54 cpu /bin/sh /root/cpu.sh
exec .1.3.6.1.4.1.2021.55 disk /bin/sh /root/disk.sh
监控主机运行
[root@localhost snmp]# snmpwalk -v 1 192.168.20.186 -c public .1.3.6.1.4.1.2021.53
UCD-SNMP-MIB::ucdavis.53.1.1 = INTEGER: 1
UCD-SNMP-MIB::ucdavis.53.2.1 = STRING: "memory"
UCD-SNMP-MIB::ucdavis.53.3.1 = STRING: "/bin/sh /root/memory.sh"
UCD-SNMP-MIB::ucdavis.53.100.1 = INTEGER: 0
UCD-SNMP-MIB::ucdavis.53.101.1 = STRING: "442"
UCD-SNMP-MIB::ucdavis.53.101.2 = STRING: "1006"
UCD-SNMP-MIB::ucdavis.53.102.1 = INTEGER: 0
根据实际输出数据是442和1006，所以可以调整最终的检查脚本
[root@localhost snmp]#snmpwalk -v 1 192.168.20.186 -c public .1.3.6.1.4.1.2021.53 | grep 53.101 | awk -F\" '{print $2}'
443
1006