$ grep -i ipv6 /boot/config-2.6.20-1.2944.fc6
CONFIG_IPV6=m
CONFIG_IPV6_PRIVACY=y
CONFIG_IPV6_ROUTER_PREF=y
CONFIG_IPV6_ROUTE_INFO=y
CONFIG_IPV6_MIP6=y
CONFIG_IPV6_SIT=m
CONFIG_IPV6_TUNNEL=m
CONFIG_IPV6_MULTIPLE_TABLES=y
CONFIG_IPV6_SUBTREES=y
# IPv6: Netfilter Configuration (EXPERIMENTAL)
CONFIG_NF_CONNTRACK_IPV6=m
CONFIG_IP6_NF_MATCH_IPV6HEADER=m