net-snmp调用脚本及独立日志配置
net-snmp可以调用外部脚本扩展功能，如：
vi /etc/snmp/snmpd.conf
exec .1.3.6.1.4.1.2021.18 tcpCurrEstab /etc/snmp/tcpconn.sh
exec .1.3.6.1.4.1.2021.19 tcpCurrHttp /etc/snmp/tcphttp.sh
exec .1.3.6.1.4.1.2021.20 tcpCurrPhp-fpm /etc/snmp/tcpphp.sh
exec .1.3.6.1.4.1.2021.21 tcpCurrMemcache /etc/snmp/tcpmemcache.sh
上面是旧版的配置，已经弃用了，新版本用：
extend .1.3.6.1.4.1.2021.18 tcpCurrEstab /etc/snmp/tcpconn.sh
extend .1.3.6.1.4.1.2021.19 tcpCurrHttp /etc/snmp/tcphttp.sh
extend .1.3.6.1.4.1.2021.20 tcpCurrPhp-fpm /etc/snmp/tcpphp.sh
extend .1.3.6.1.4.1.2021.21 tcpCurrMemcache /etc/snmp/tcpmemcache.sh
snmpd想允许一个段访问，配置为：com2sec notConfigUser 192.168.1.0/24 public
[root@ha1 log]# cat /etc/snmp/tcpconn.sh
#!/bin/sh
conn=netstat -s -t | grep connections established |awk '{print 1}'
echo conn
[root@ha1 log]# cat /etc/snmp/tcphttp.sh
#!/bin/sh
netstat -an | grep ‘:80 ‘ | grep ESTABLISHED | wc -l
[root@ha1 log]# cat /etc/snmp/tcpmemcache.sh
#!/bin/sh
netstat -an | grep :11211 | grep ESTABLISHED | wc -l
[root@ha1 log]# cat /etc/snmp/tcpphp.sh
#!/bin/sh
netstat -an | grep :9000 | grep ESTABLISHED | wc -l
重启net-snmpd:
service snmpd restart
测试：
[root@ha1 log]# snmpwalk -v 2c -c public 192.168.1.4 .1.3.6.1.4.1.2021.18
UCD-SNMP-MIB::ucdavis.18.1.1 = INTEGER: 1
UCD-SNMP-MIB::ucdavis.18.2.1 = STRING: “tcpCurrEstab”
UCD-SNMP-MIB::ucdavis.18.3.1 = STRING: “/etc/snmp/tcpconn.sh”
UCD-SNMP-MIB::ucdavis.18.100.1 = INTEGER: 0
UCD-SNMP-MIB::ucdavis.18.101.1 = STRING: “5023”
UCD-SNMP-MIB::ucdavis.18.102.1 = INTEGER: 0
UCD-SNMP-MIB::ucdavis.18.103.1 = “”
有信息输出就表明成功了。
默认net-snmpd输出日志到/var/log/messes，想输出至一个独立日志文件，配置为：
vi /etc/sysconfig/snmpd.options
# snmpd command line options
# OPTIONS=”-Lsd -Lf /dev/null -p /var/run/snmpd.pid -a”
OPTIONS=”-Lf /var/log/snmpd.log”
重启net-snmpd:
service snmpd restart
查看日志：
cat /var/log/snmpd.log
