IPv6 address, either the full eight-hextet form or a form compressed with a single :: (leading, middle or trailing). Lookarounds instead of \b let a leading :: anchor and stop the match at a stray colon. The hextet count across the :: is not verified, and IPv4-suffixed forms (::ffff:192.0.2.1) are only partially covered.
Label: IPV6
(?<![:\w])(?:(?:[0-9A-Fa-f]{1,4}:){7}[0-9A-Fa-f]{1,4}|(?:[0-9A-Fa-f]{1,4}:){1,7}:(?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4}){0,6})?|::[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4}){0,6})(?![:\w])Node 2001:db8:85a3:0000:0000:8a2e:0370:7334 is up. → 2001:db8:85a3:0000:0000:8a2e:0370:7334Listening on 2001:db8::1 port 8080. → 2001:db8::1Loopback ::1 answered. → ::1Prefix 2001:db8:: is reserved. → 2001:db8::std::vector<int> v;Meeting at 12:30:45 todayMAC 00:1a:2b:3c:4d:5eTags: international, network