Werk #18050: Support for IPv6 in Smart Ping
| Component | Core & setup | ||
| Title | Support for IPv6 in Smart Ping | ||
| Date | May 8, 2025 | ||
| Level | Prominent Change | ||
| Class | New Feature | ||
| Compatibility | Incompatible - Manual interaction might be required | ||
| Checkmk versions & editions |
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For products using Checkmk Micro Core, Smart Ping is a higher performance feature for verifying the reachability of hosts.
It is leaner and does ICMP checks on a regular interval, with the caveat that no metrics are generated for the host.
To read more information about Smart Ping, see our documentation here: docs.checkmk.com/latest/en/cmc_differences.html#smartping
Previously, Smart Ping only supported hosts with IPv4 addresses.
With this update, Smart Ping now supports sending ICMPv6 ping packets to IPv6 hosts. In addition, it also supports listening for IPv6 packets from the same hosts, whether the protocol is ICMPv6 or any TCP-based protocol.
Does this affect you?
If your site only has IPv4 addresses, then no. The Smart Ping behavior is the same as before.
However, if you had an IPv6 host or a dual-stack host with the IPv6 address set as the primary address, the previous behavior was to use a regular ping check and you will be affected.
With this update, Smart Ping is now used by default which means there will no longer be metrics generated for the host. Such metrics included Round trip average and Packet loss.
To restore using a regular ping check and thus being able to generate metrics again for the host, there are two options:
- Add a rule to the Host check command ruleset which sets the Host check command to PING (active check with ICMP echo request) for hosts matching the rule specified.
- This matches the previous implicit behavior before the update.
- Add a rule to the Check hosts with PING (ICMP Echo Request) ruleset which adds a service to the hosts matching the rule specified.
Additionally, dual-stack hosts have the following considerations:
- The behavior of the ping which is sent out depends on the Primary IP address family of dual-stack hosts ruleset:
- The default value is to use IPv4.
- Regardless of the value, the ping will always follow the Host check command rule, whereas the previous version would fall back to doing an active ping for IPv6 because of the lack of Smart Ping support.
- A ping service is created for the alternative address of the host:
- These ping services will generate metrics for the host but only for the alternative address.
- Thus, if the primary address for your host is IPv6 the ping service which is added will be for IPv4, and vice versa when the primary address is IPv4 (the ping service will be IPv6).
- Consider the aforementioned check rulesets for doing active checks for the primary address too if this suits your use case.