Merge pull request #5334 from BradKollmyer/dhcp-interface-mtu-u16

dhcp-server: T9093: allow option interface-mtu up to 16000

Author: c-po

interface-definitions/include/dhcp/option-v4.xml.i

@@ -87,11 +87,11 @@
       <properties>
         <help>Interface MTU</help>
         <valueHelp>
-          <format>u16:576-9000</format>
+          <format>u16:576-16000</format>
           <description>Client interface MTU</description>
         </valueHelp>
         <constraint>
-          <validator name="numeric" argument="--range 576-9000"/>
+          <validator name="numeric" argument="--range 576-16000"/>
         </constraint>
       </properties>
     </leafNode>

smoketest/scripts/cli/test_service_dhcp-server.py

@@ -420,7 +420,9 @@ def test_dhcp_single_pool_options(self):
         server_identifier = bootfile_server
         ipv6_only_preferred = '300'
         capwap_access_controller = '192.168.2.125'
-        interface_mtu = '1420'
+        # 9216: jumbo-fabric MTU above the former arbitrary 9000 cap
+        # (DHCP option 26 is a full u16)
+        interface_mtu = '9216'
 
         pool = base_path + ['shared-network-name', shared_net_name, 'subnet', subnet]
         self.cli_set(pool + ['subnet-id', '1'])