After install zabbix agent 2.2 from epel and add servers to zabbis server i catch errors in log file: "failed: another network error, wait for 15 seconds".
After turn on debug log errors changed to: "ZBX_TCP_READ() failed: [4] Interrupted system call", and from network dump i see that agent hangup and dont send data more than 20 sec for each request.
Upgrade to zabbix agent 2.4.5 dont solve the problem.

After change Server= parameter in agent conf file error is gone.

Hosting provider DNS server dont have any rate limit, so i think there is some bug in agent.