Custom Checks

[rbourgaize]

OK, so I am at a loss here.
Got Zabbix running well, ICMP queries, agent installs and some SNMP stuff. Bloody marvellous stuff!
But something that I feel should be so simple, is causing me so much of a headache.
I monitor multiple DNS servers, which due to the nature of the environment they sit it, it is not feasible to have an agent installed on them. All I want to do, is to run a 'dig +short hostname @serverIwantTOtest' against multiple DNS servers. Then compare the result of this against a predefined answer.

So for example:
"dig +short www.bbc.net.uk"
if answer is not 212.58.249.215
then alert

But for the life of me, I just cant seem to figure out how to do it.

If it helps, I am running Zabbix 4

Many thanks to anyone that can help.

[max.ch.88]

https://www.zabbix.com/documentation/4.0/manual/config/items/itemtypes/zabbix_agent

You could use the item net.dns.record[<ip>,name,<type>,<timeout>,<count>,<protocol>] or write own script and use it over userparameter https://www.zabbix.com/documentation...userparameters

[rbourgaize]

Hi Max,

Thank you for this.
For example, checking Google's DNS (8.8.8.8) is resolving, what I did was :

- On Zabbix server, configure the zabbix_agent.conf with:
UserParameter=ns1dig.dns,dig cisco.co.uk +short @8.8.8.8

- On Zabbix WebGUI, create a host named 'GoogleDNS' with the Agent Interface IP as the Zabbix server (essentially using the local agent on the server)

- In the 'GoogleDNS' host, create a new Item:
Name = DNS Check
Type = Zabbix Agent
Key = ns1dig.dns
Update Interval = 30s

- In the 'GoogleDNS' host, create a new trigger:
Name = Name Resolution Failed
Severity = High
Expression = {GoogleDNS:ns1dig.dns.str(72.163.4.154,#2)}=0
OK Event = Expression
Problem event = Single
OK Event = All Problems
Description = DNS Server has failed to resolve DNS query 2 times in a row.

This now flags an alarm if the DNS resolver fails twice in a row, which can be adjusted by changing the '#2' to any number in the Expression.

So this works really well which I have now used for some of my DNS hosts, but will take quite a bit of time to do for my 20+ other DNS servers. Any idea on how I could apply this as a template? If not, your advice for this has been very helpful, an I will continue to use it in this way.

[max.ch.88]

You will get the same result using the item with key net.dns.record[<ip>,name,<type>,<timeout>,<count>,<protocol>]. In that case you don't need to write the userparameter.
I would advise to create a new template with the item net.dns.record[8.8.8.8,{HOST.HOST},A] and to link it to hosts with names like cisco.co.uk, www.bbc.net.uk ...