A. 选项在消息类型中的出现情况

下表用 "*" 标出各个 DHCP 消息类型中允许出现的选项:

       Client Server IA_NA  Option Pref  Time Relay Auth. Server
         ID     ID   IA_TA  Request            Msg.       Unica.

Solicit * * * * * Advert. * * * * * Request * * * * * * Confirm * * * * * Renew * * * * * * Rebind * * * * * Decline * * * * * * Release * * * * * * Reply * * * * * * Reconf. * * * * Inform. * (see note) * * * R-forw. * * R-repl. * *

注 (NOTE):

  仅出现在为响应 Reconfigure 而发送的 Information-Request 消息中 (见第 19.4.3 节).

        Status  Rap. User  Vendor Vendor Inter. Recon. Recon.
         Code  Comm. Class Class  Spec.    ID    Msg.  Accept

Solicit * * * * * Advert. * * * * * Request * * * * Confirm * * * Renew * * * * Rebind * * * * Decline * * * Release * * * Reply * * * * * * Reconf. * Inform. * * * * R-forw. * * * * R-repl. * * * *