Multiple Routes with Hex String in DHCP option 249
03/26/2020 7 12378
This article covers how to configure multiple routes with hex string in DHCP option 249 (Private Use) on a SonicWall firewall.
STEP 1: Create Option Object
Go to Network | DHCP Server screen,
Step 2: Now, click on Advanced,
Step 3: Click DHCP Generic Option drop down Menu and select "Create New DHCP Option Object"
Step 4: Now, you have to fill up all the necessary fields,
OPTION NAME is the name of the object, OPTION NUMBER chosen is "DHCP Option 249" with OPTION ARRAY check-box "DISABLED" and OPTION TYPEset as "HEX STRING".
Example: You have to Add two Routes:
1)Network is 10.56.0.0/16 and Gateway is 10.10.5.253 and
2)Network is 10.58.0.0/16 and Gateway is 10.10.5.253
When using Option Type as Hex String we have to convert each Decimal to its Hexadecimal value and add them in a continuous line but we have to separate each route with a SPACE/ENTER.
In Order to convert a Decimal to its Hexadecimal value follow this link:
Now, before converting the Decimals to Hexadecimals you have to write the whole Route in the following patter:
"16;10;56;10;10;5;253" and start converting the Decimals starting from Left side i.e. 16;x;x;x;x;x;x as shown in the image below:
Now the syntax that we have to use in this scenario goes as follows:
100A380A050101 FOR Network 10.56.0.0/16 and Gateway 10.10.5.253 (16;10;56;10;10;5;253)
100A380A050101100A3A0A050101 FOR Network 10.58.0.0/16 and Gateway 10.10.5.253 (16;10;58;10;10;5;253)
Step 5: In order to Verify the same, you can run a packet capture on WIRESHARK and the results should be as follows: