Insert route using DHCP Option 249

Microsoft has introduced DHCP Option 249 to insert classless static routes into the DHCP client using DHCP Server.

You can add multiple routes into DHCP Client using Option 249.Each routes consists of the Destination descriptor and Router IP address.Destination descriptors describe the IP subnet number and subnet mask of a particular destination.If DHCP Client do not support this option will ignore if its recevied option 249 from a DHCP Server.If DHCP Client support option 33 and 249 and DHCP Server offer both option.The DHCP Client will ignore the option 33 and install route based on option 249. Option 33 will allow you to insert static routes on your DHCP configuration but it will only accept classful network.

Step 1 : By default Infoblox does not load with option 249 so we need to create option 249.Hence follow the steps below to create option 249.

Data Management ---> DHCP----> Option Space

Tick DHCP checkbox and click on Edit <right side corner)

Click on Plus sign to add new DHCP Option.

Name : option-249

Code : 249

Type : array of 8-bit unsigned integer

Save & close

Step 2 : Now we need to configure Option 249 for the desired subnet.

Data Management ---> DHCP----> Networks

Tick Network(desired subnet) checkbox and click on Edit <right side corner)

Go on IPV4 DHCP Options and add the DHCP Option 249 in custom DHCP Option.

Note : If you are not seeing option 249 which means You have not configured the option 249 correctly.

Step 3 : Now you define the destination descriptor and route address.

<subnet Mask>,<IP address>,<Gateway>

22,192.168,1, 192,168,188,16

22 - Subnet mask

192,168,1 - Classless Subnet.

You do not need to define Zero into subnet.

192,168,188,16 - Route address

Please not all value you need to define by comma and you will need one space between destination descriptor and router address.

Save & Close

Step 4 : Restart the DHCP server as required to update the DHCP Client Config.

Once DHCP Client start asking for IP address , gateway etc.You will see client recevied the desired classless route in Option 249.

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