ICMP support is implemented for both IPv4 and IPv6 addresses, using the operating system's host name resolution (via resolve-host):

icmp

<icmp> ( host -- icmp )

IPv4 addresses, with no host name resolution:

icmp4

<icmp4> ( host -- icmp4 )

IPv6 addresses, with no host name resolution:

icmp6

<icmp6> ( host -- icmp6 )