[5376] Addressed review comments.

Updated User's Guide and rename function.

doc/guide/dhcp4-srv.xml

@@ -3852,17 +3852,9 @@ i.e. it will assign increasing integer values starting from 1.</para>
 
       <para>
         It is possible to override default server identifier values by specifying
-        "dhcp-server-identifier" option. This option can be specified at any
-        configuration level, but it is recommended to only specify this option on
-        global, shared network or subnet level. Specifying this option on a class
-        or host reservation level will work only in cases when the specified
-        server identifier is an IP address assigned to one of the interfaces on
-        which the server is listening to DHCP queries. Otherwise, the server
-        will drop the messages with these server identifiers. The server will
-        accept messages including server identifiers specified on the global,
-        shared network and subnet level, even if they point to IP addresses not
-        assigned to any interfaces, on which the server is listening to the
-        DHCP queries.
+        "dhcp-server-identifier" option. This option is only supported on the
+        global, shared network and subnet level. It must not be specified
+        on client class and host reservation level.
       </para>
 
       <para>

src/bin/dhcp4/dhcp4_srv.cc

@@ -2863,7 +2863,7 @@ Dhcpv4Srv::acceptServerId(const Pkt4Ptr& query) const {
     // This server identifier is not configured for any of the subnets, so
     // check on the shared network level.
     CfgSharedNetworks4Ptr cfg_networks = cfg->getCfgSharedNetworks4();
-    if (cfg_networks->hasSubnetWithServerId(server_id)) {
+    if (cfg_networks->hasNetworkWithServerId(server_id)) {
         return (true);
     }
 

src/lib/dhcpsrv/cfg_shared_networks.cc

@@ -13,7 +13,7 @@ namespace isc {
 namespace dhcp {
 
 bool
-CfgSharedNetworks4::hasSubnetWithServerId(const IOAddress& server_id) const {
+CfgSharedNetworks4::hasNetworkWithServerId(const IOAddress& server_id) const {
     const auto& index = networks_.get<SharedNetworkServerIdIndexTag>();
     auto network_it = index.find(server_id);
     return (network_it != index.cend());

src/lib/dhcpsrv/cfg_shared_networks.h

@@ -119,7 +119,7 @@ public:
     /// @param server_id Server identifier.
     ///
     /// @return true if there is a network with a specified server identifier.
-    bool hasSubnetWithServerId(const asiolink::IOAddress& server_id) const;
+    bool hasNetworkWithServerId(const asiolink::IOAddress& server_id) const;
 
 
 };