title: zabbix-agent active config: ZBX_TCP_READ() failed
body: <p>I'm using <code>Zabbix 2.2.6</code> for both server and clients and trying to configure <code>zabbix-agent</code> works only for active mode. Basically I set on <code>/etc/zabbix/zabbix_agentd.conf</code> </p>
  
  <pre><code>ServerActive=zabbix_server_ip
  StartAgents=0
  </code></pre>
  
  <p>I clone 2 templetes in zabbix server web GUI <code>Template App Zabbix Agent Active</code> and change all item type to <code>Zabbix agent active</code> mode. Then add the client and link to that template.</p>
  
  <p>I also open firewall on Zabbix server port <code>10050</code> and <code>10051</code> for client. On client I can <code>telnet</code> and check that connection is okay for those 2 ports. But I still got this error:</p>
  
  <pre><code>active check configuration update from [zabbix_server_ip:10051] started to fail (ZBX_TCP_READ() failed: [104] Connection reset by peer)
  </code></pre>
  
  <p>On passive mode everything work fine except sometimes it returns the anyoing error:</p>
  
  <pre><code>Zabbix agent on MY_CLIENT_NODE is unreachable for 5 minutes
  </code></pre>
  
  <p>I think switch to <code>active</code> mode can solve this problem since I update the server to latest version of 2.2.x.</p>
  
  <p>Please give me suggest about this case.</p>