title: How to recognize Network Gateway VLAN for SoftLayer
body: <p>What I'm trying to get is how to understand that a VLAN is a network gateway one.</p>
  
  <p>I'm trying to find all private Washington 4 datacenter and from the API I can get 4 vlans, but the portal allows to select one of 3 vlans. 
  It seems this subnet/vlan cannot be used:</p>
  
  <pre><code>{"broadcastAddress"=&gt;"10.170.23.127",
   "cidr"=&gt;26,
   "gateway"=&gt;"10.170.23.65",
   "id"=&gt;1087855,
   "isCustomerOwned"=&gt;false,
   "isCustomerRoutable"=&gt;false,
   "modifyDate"=&gt;"2016-02-03T14:51:45-05:00",
   "netmask"=&gt;"255.255.255.192",
   "networkIdentifier"=&gt;"10.170.23.64",
   "networkVlanId"=&gt;1158237,
   "sortOrder"=&gt;"4",
   "subnetType"=&gt;"PRIMARY",
   "totalIpAddresses"=&gt;"64",
   "usableIpAddressCount"=&gt;"61",
   "version"=&gt;4,
   "addressSpace"=&gt;"PRIVATE",
   "datacenter"=&gt;{"id"=&gt;957095, "longName"=&gt;"Washington 4", "name"=&gt;"wdc04", "statusId"=&gt;2},
   "networkVlan"=&gt;
    {"accountId"=&gt;872113,
     "id"=&gt;1158237,
     "modifyDate"=&gt;"2016-02-04T12:57:26-05:00",
     "name"=&gt;"RZ",
     "primarySubnetId"=&gt;1087855,
     "attachedNetworkGatewayFlag"=&gt;false,
     "vlanNumber"=&gt;844}}
  </code></pre>
  
  <p>If I pass this vlan id to request an order, I receive this error:</p>
  
  <pre><code>The backend VLAN #1158237 is a Network Gateway VLAN. 
  </code></pre>
  
  <p>So this vlan cannot be used and the portal filters it out. That's ok, but the question is how to understand that this vlan should not be used?</p>
  
  <p>Initially I thought attachedNetworkGatewayFlag will help, but it always false(see above). Any other property could be used here?</p>