Set environment

• zabbix server
• zabbix active proxy in docker, image zabbix/zabbix-proxy-sqlite3:ubuntu-7.4.1
• passive zabbix agent monitored by proxy

Up DNS server:
load db.home-local.lab.hm, db.gj.zbx.local, Corefile, docker-compose.yml in same directory, in files db.home-local.lab.hm and db.gj.zbx.local set propper IPs. Than use docker-compose.yml to up the DNS server.

Steps to reproduce:

• Add host that monitored by proxy and use full DNS names. Everything should work as expected.
• Edit on the VM /etc/resolv.config in a way to use short names as in the file resolv.conf . Replace nameserver IP file and restart proxy container. Replace in the frontend Agent Interface to use short name. On this stage everything also should work as expected.
• Edit /etc/resolv.config

  options edns0 trust-ad ndots:0
  

• Here is a bug: you still could use agent short name in zabbix_get from proxy container, item test from the frontend will be successful but monitoring will experience network error and stops and Agent interface will become unavailable because of DNS error: Get value from agent failed: Cannot resolve address: non-recoverable failure in name resolution
  If you switch the Interface to IP or full DNS name the monitoring will be restored.

Expected:
If item test or zabbix_get is successful than measurement should be collected and interface available.