<div class="content"><p> </p><p>The <b>R_DhcpModifyClass</b> method modifies the user class
or vendor class definition for the DHCP server.</p><dl>
<dd>
<div><pre> DWORD R_DhcpModifyClass(
   [in, unique, string] DHCP_SRV_HANDLE ServerIpAddress,
   [in] DWORD ReservedMustBeZero,
   [in] LPDHCP_CLASS_INFO ClassInfo
 );
</pre></div>
</dd></dl><p><b>ServerIpAddress: </b>The IP address/host name of
the DHCP server. This parameter is unused.</p><p><b>ReservedMustBeZero: </b>This is of type <span><a href="../ms-dtyp/262627d8-3418-4627-9218-4ffe110850b2" data-linktype="relative-path">DWORD</a></span>
and is reserved for future use. Currently it is not used, and any value set to
this parameter will not affect the behavior of this method.</p><p><b>ClassInfo: </b>This is of type <span><a href="0f8461a3-14ad-4b60-a398-553b199ecfc0" data-linktype="relative-path">LPDHCP_CLASS_INFO (section 2.2.1.2.75)</a></span>
structure, containing the information about the class.</p><p><b>Return Values: </b>A 32-bit unsigned integer value
that indicates return status. A return value ERROR_SUCCESS (0x00000000)
indicates that the operation was completed successfully, else it contains a
Win32 error code, as specified in <span><a href="../ms-erref/1bc92ddf-b79e-413c-bbaa-99a5281a6c90" data-linktype="relative-path">[MS-ERREF]</a></span>.
This error code value can correspond to a DHCP-specific failure, which takes a
value between 20000 and 20099, or any generic failure.</p><dl>
<dd>
<table><thead>
  <tr>
   <th>
   <p>Return value/code</p>
   </th>
   <th>
   <p>Description</p>
   </th>
  </tr>
 </thead><tbody><tr>
  <td>
  <p>0x00000000</p>
  <p>ERROR_SUCCESS</p>
  </td>
  <td>
  <p>The call was successful.</p>
  </td>
 </tr><tr>
  <td>
  <p>0x00004E4C</p>
  <p>ERROR_DHCP_CLASS_NOT_FOUND</p>
  </td>
  <td>
  <p>The class name being used is unknown or incorrect.</p>
  </td>
 </tr></tbody></table>
</dd></dl><p>The opnum field value for this method is 25.</p><p>When processing this call, the DHCP server MUST do the
following:</p><ul><li><p><span><span> 
</span></span>Validate if this method is authorized for read/write access per
section <span><a href="38840bd0-0a5a-47ed-bc69-0dd870d33aec" data-linktype="relative-path">3.5.5</a></span>. If not,
return the error ERROR_ACCESS_DENIED.</p>
</li><li><p><span><span> 
</span></span>Validate the parameter <i>ClassInfo</i>. If it is NULL, return
ERROR_INVALID_PARAMETER.</p>
</li><li><p><span><span> 
</span></span>Validate the fields <b>ClassName</b>, <b>ClassData</b>, and <b>ClassDataLength</b>
in the <i>ClassInfo</i> structure. If the <b>ClassName</b> or the <b>ClassData</b>
field is NULL or if the <b>ClassDataLength</b> field is 0, return
ERROR_INVALID_PARAMETER.</p>
</li><li><p><span><span> 
</span></span>Retrieve the <b>DHCPv4ClassDef</b> entry that has the <b>ClassName</b>
member equal to <b>ClassName</b> member of <i>ClassInfo</i> from the server ADM
element <b>DHCPv4ClassDefList</b>.</p>
</li><li><p><span><span> 
</span></span>If the <b>DHCPv4ClassDef</b> entry corresponding to the <b>ClassName</b>
field of the <i>ClassInfo</i> parameter is not found, return
ERROR_DHCP_CLASS_NOT_FOUND.</p>
</li><li><p><span><span> 
</span></span>Copy information from the fields of the <i>ClassInfo</i>
parameter into the <b>DHCPv4ClassDef</b> members to modify the <b>DHCPv4ClassDef</b>
object found, and return ERROR_SUCCESS.</p>
</li></ul><p><b>Exceptions Thrown:</b> No exceptions are thrown beyond
those thrown by the underlying RPC protocol specified in <span><a href="../ms-rpce/290c38b1-92fe-4229-91e6-4fc376610c15" data-linktype="relative-path">[MS-RPCE]</a></span>.</p></div>