File dhclient6.conf of Package dhcp

# Client configuration file example for DHCPv6

option dhcp6.rfc4833-tz-posix-string code 41 = string;
option dhcp6.rfc4833-tz-name code 42 = string;

# The client side command to enable rapid-commit (2 packet exchange)
send dhcp6.rapid-commit;

# name-servers and domain-search are requested by default.
# here is the way to request sip-servers-addresses too
also request dhcp6.sip-servers-addresses,
             dhcp6.rfc4833-tz-posix-string, dhcp6.rfc4833-tz-name;