https://github.com/logstash-plugins/logstash-patterns-core/blob/7f94275ec8212f7f0aa6eb4ac5dbf3d70cd05cac/patterns/ecs-v1/grok-patterns#L28 [Some IPv6 can have a suffix](https://superuser.com/questions/99746/why-is-there-a-percent-sign-in-the-ipv6-address); the IP pattern could include this too. Example: "ip"=>"fe80::12e:d4f:c66c:d570%2"