3.1.4.2 Sending a DHCPv6 Solicit, Request, or Information-request Message

When sending a DHCPv6 Solicit, Request, or Information-request message, DHCPv6 clients implementing this specification SHOULD<25> include a Vendor Class Option formatted as in section 2.2.5.

When sending an Information-request message, DHCPv6 clients implementing this specification MAY<26> include an OPTION_ORO (Option 6) with OPTION_USER_CLASS (Option 15) as the only requested option.