It would be nice to have dedicated IPv6 simple checks - to have the possibility to monitor ipv6 and ipv4 in parallel on a host.

Just add a dedicated flag to every simple check - example:

 icmppingsec[<target>,<packets>,<interval>,<size>,<timeout>,<mode>,<protocol>] 

The value of <protocol>" might be:

• v6: use ipv6 only, if agent interface is configured to a ipv4 ip fail item, if agent interface is configured to dns use AAAA record
• v4: use ipv4 only, if agent interface is configured to a ipv6 ip fail item, if agent interface is configured to dns use A record
• ipv4prefer: use ipv4 over ipv6, if using a dns name
• ipv6prefer: use ipv6 over ipv4, if using a dns name
• ....

Further hints:

• there might be also other types items which should distinguish ipv6 and ipv4
• If choosing "dns" as agent interface in the host configuration, it might be useful to have the possibility configure a preference or a dedicated type of network connectivity