change /etc/hosts. For every entry related to local host (INCLUDING ipv6 entries), map to localhost, e.g.:
::1 localhost #ip6-localhost ip6-loopback
fe00::0 localhost #ip6-localnet
ff00::0 localhost #ip6-mcastprefix
ff02::1 localhost #ip6-allnodes
ff02::2 localhost #ip6-allrouters