007-zabbix Server 4.0 监控TCP的12种状态

大家对TCP三次握手比较熟悉了，都知道当发生DOSS攻击时，客户端发送SYN给服务端后，服务端响应SYN+ACK，此时客户端就不回应服务端ACK啦（如果正常建立三次握手客户端会回应ACK，表示三次握手建立成功，服务端状态变为ESTABLISED状态，不了解的小伙伴可以自行百度。），这会导致服务端的SYN-RCVD状态偏多。因此监控TCP的连接数还是很有必要的，当某个SYN-RCVD偏多时，我们就可能猜测服务有异常了，需要人工介入处理。接下来我们就看看zabbix是如何监控TCP的11中状态的。

一.TCP状态扫盲

1>.三次握手

　　参考链接：https://baike.baidu.com/item/%E4%B8%89%E6%AC%A1%E6%8F%A1%E6%89%8B/5111559?fr=aladdin。

2>.使用netstat命令工具查看TCP的状态

 

按 Ctrl+C 复制代码

按 Ctrl+C 复制代码

 3>.命令行中查看服务器TCP的某种状态

[root@node102.yinzhengjie.org.cn ~]# netstat -ant | grep -c LISTEN
4
[root@node102.yinzhengjie.org.cn ~]# 

二.zabbix监控TCP状态案例并自定义模板

1>.在zabbix agent端自定义key并重启服务

[root@node102.yinzhengjie.org.cn ~]# cat /etc/zabbix/zabbix_agentd.d/TCP_STATUS.conf
UserParameter=TCP_STATUS[*],netstat -ant | grep -c $1
[root@node102.yinzhengjie.org.cn ~]# 

[root@node102.yinzhengjie.org.cn ~]# systemctl restart zabbix-agent
[root@node102.yinzhengjie.org.cn ~]#
[root@node102.yinzhengjie.org.cn ~]# systemctl status zabbix-agent
● zabbix-agent.service - Zabbix Agent
   Loaded: loaded (/usr/lib/systemd/system/zabbix-agent.service; enabled; vendor preset: disabled)
   Active: active (running) since Tue 2019-05-07 07:53:16 PDT; 4s ago
  Process: 9416 ExecStop=/bin/kill -SIGTERM $MAINPID (code=exited, status=0/SUCCESS)
  Process: 9419 ExecStart=/usr/sbin/zabbix_agentd -c $CONFFILE (code=exited, status=0/SUCCESS)
 Main PID: 9422 (zabbix_agentd)
   CGroup: /system.slice/zabbix-agent.service
           ├─9422 /usr/sbin/zabbix_agentd -c /etc/zabbix/zabbix_agentd.conf
           ├─9423 /usr/sbin/zabbix_agentd: collector [idle 1 sec]
           ├─9424 /usr/sbin/zabbix_agentd: listener #1 [waiting for connection]
           ├─9425 /usr/sbin/zabbix_agentd: listener #2 [waiting for connection]
           ├─9426 /usr/sbin/zabbix_agentd: listener #3 [waiting for connection]
           └─9427 /usr/sbin/zabbix_agentd: active checks #1 [idle 1 sec]

May 07 07:53:16 node102.yinzhengjie.org.cn systemd[1]: Starting Zabbix Agent...
May 07 07:53:16 node102.yinzhengjie.org.cn systemd[1]: PID file /run/zabbix/zabbix_agentd.pid not readable (yet?) after start.
May 07 07:53:16 node102.yinzhengjie.org.cn systemd[1]: Started Zabbix Agent.
[root@node102.yinzhengjie.org.cn ~]# 

2>.服务端验证zabbix agent自定义的key是否生效

[root@node101.yinzhengjie.org.cn ~]# yum -y install zabbix-get
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
epel/x86_64/metalink                                                                                                                                                                                       | 6.0 kB  00:00:00
 * base: mirrors.aliyun.com
 * epel: mirrors.tuna.tsinghua.edu.cn
 * extras: mirrors.aliyun.com
 * updates: mirrors.aliyun.com
base                                                                                                                                                                                                       | 3.6 kB  00:00:00
epel                                                                                                                                                                                                       | 4.7 kB  00:00:00
extras                                                                                                                                                                                                     | 3.4 kB  00:00:00
mysql-connectors-community                                                                                                                                                                                 | 2.5 kB  00:00:00
mysql-tools-community                                                                                                                                                                                      | 2.5 kB  00:00:00
mysql56-community                                                                                                                                                                                          | 2.5 kB  00:00:00
updates                                                                                                                                                                                                    | 3.4 kB  00:00:00
zabbix                                                                                                                                                                                                     | 2.9 kB  00:00:00
zabbix-non-supported                                                                                                                                                                                       |  951 B  00:00:00
(1/5): extras/7/x86_64/primary_db                                                                                                                                                                          | 201 kB  00:00:00
epel/x86_64/primary_db         FAILED
https://mirrors.tuna.tsinghua.edu.cn/epel/7/x86_64/repodata/b46e7947260ac0114fc1b48c782d12377659fe2b8f565a55bcab0cf98b124aa1-primary.sqlite.bz2: [Errno 14] HTTPS Error 404 - Not Found         ]  0.0 B/s |    0 B  --:--:-- ETA
Trying other mirror.
To address this issue please refer to the below wiki article 

https://wiki.centos.org/yum-errors

If above article doesn't help to resolve this issue please use https://bugs.centos.org/.

(2/5): mysql-tools-community/x86_64/primary_db                                                                                                                                                             |  58 kB  00:00:00
(3/5): epel/x86_64/updateinfo                                                                                                                                                                              | 994 kB  00:00:01
(4/5): updates/7/x86_64/primary_db                                                                                                                                                                         | 4.2 MB  00:00:01
(5/5): epel/x86_64/primary_db                                                                                                                                                                              | 6.7 MB  00:00:04
Resolving Dependencies
--> Running transaction check
---> Package zabbix-get.x86_64 0:4.0.7-1.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

==================================================================================================================================================================================================================================
 Package                                                 Arch                                                Version                                                    Repository                                           Size
==================================================================================================================================================================================================================================
Installing:
 zabbix-get                                              x86_64                                              4.0.7-1.el7                                                zabbix                                              282 k

Transaction Summary
==================================================================================================================================================================================================================================
Install  1 Package

Total download size: 282 k
Installed size: 1.1 M
Downloading packages:
zabbix-get-4.0.7-1.el7.x86_64.rpm                                                                                                                                                                          | 282 kB  00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : zabbix-get-4.0.7-1.el7.x86_64                                                                                                                                                                                  1/1
  Verifying  : zabbix-get-4.0.7-1.el7.x86_64                                                                                                                                                                                  1/1 

Installed:
  zabbix-get.x86_64 0:4.0.7-1.el7                                                                                                                                                                                                 

Complete!
[root@node101.yinzhengjie.org.cn ~]# 

[root@node101.yinzhengjie.org.cn ~]# zabbix_get -s node102.yinzhengjie.org.cn -k TCP_STATUS[LISTEN]　　　　　　　　　　#需要注意的是:这样取值其实在客户端是以zabbix用户进行取值操作，有些命令需要root用户权限才能执行，因此我们要考虑命令权限的问题哟！
4
[root@node101.yinzhengjie.org.cn ~]# 

3>.在zabbix web页面中创建模板

4>.填写相应参数并添加模板

5>.模板添加成功

6>.为模板添加监控项（item）

7>.监控ESTABLISHED状态

8>.克隆上述操作，将其他11中状态监控起来

9>.TCP的12中状态照单全收

三.使用自定义模板

1>.配置主机的监控信息

2>.链接我们自定义的模板

3>.自定义zabbix监控项

4>.刷新配置并查看最新数据

[root@node101.yinzhengjie.org.cn ~]# zabbix_server -R config_cache_reload　　　　　　　　　　　　　　　　#在zabbix server端刷新一下配置
zabbix_server [10628]: command sent successfully
[root@node101.yinzhengjie.org.cn ~]# 

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