Values from wrong client

[Sebneu]

Hi everyone

Our clients are accessed via DNS. They get their addresses via DHCP.

With road warriors connecting with vpn it is possible that our dns server stores one IP address for two clients. IP addresses are provided by the vpn endpoint, being our firewall. E.g. client A might disconnected and the next client connecting might get the same IP address.There are no parameters for that dhcp 'server' I could adjust - the firewall dhcp is rather dumb. So neither the client nor the dhcp server will tell the dns that it should release that entry. Usually this is no problem either.

Now, it is possible that client A disconnects and zabbix server still tries to retrieve values from that client - it might ask the dns server for the ip address and dns will deliver an IP address - the old one. When client B connects and gets the same IP address, the dns will add that address, too. And when zabbix server will be able to connect to that IP, thinking it is connected to client A again and will happily receive values from client B in the name of client A. So, all values for client A get massed up.

Is there a way that zabbix server checks, if the name of the client is the same as it is trying to connect to?
What other solutions are there?

Regards
SebNeu

[LenR]

I think switching to agent_active would fix that.

[LenR]

I think switching to agent_active would fix that.

[cyber]

By default agent registers with IP address. You can force agent registration by name... https://www.zabbix.com/documentation...ault-interface

[Sebneu]

Thanks for the replies

@LenR: I will give it a try
@cyber: we are not using auto registration. Would that give an advantage?

Regards
SebNeu

[cyber]

Thanks for the replies

@LenR: I will give it a try
@cyber: we are not using auto registration. Would that give an advantage?

Regards
SebNeu

Even if no autoreg... if you turn to DNS name, then it is first resolved, and then your server turns to correct IP hopefully...

[Sebneu]

That's the actual problem: At that moment the client is not available, nevertheless the dns gives the old IP when the client was available - even though that IP was given to another host in the meantine.

All workstations are using dhcp (servers do not). In zabbix the connection to the agent is defined to use DNS.

[Sebneu]

Hi

changing to zabbix agent active makes the data look much more reasonable.

Thank you for your suggestion!

Regards
Sebneu