Handy tool: DHCP Option 43 builder

Question

http://shimi.net/services/opt43/

Author says: "You're welcome to use; Disclaimer: Not really debugged, I take no responsibility for errors or for the availability of the service in the future;"

but if you've ever struggled with all the hex...you'll appreciate it!

abilash_p_r · Answer

Hi Ali,

DHCP Option 43 for ZD and vSZ can be calculated as below.

Let us assume 10.10.10.10 is the IP address of ZD/vSZ/SZ, the formula would be.

Sub option (ZD:03) or (vSZ:06) + Length of the IP in HEX + HEX Value of the IP (ASCII to HEX).

Lets apply above formula on IP 10.10.10.10

Sub Option ZD = 03

Length of IP in HEX

10.10.10.10 has a length of 11 or hex value of 0x0b = 0b

Example string length for different IP:

10.9.52.32 has a length of 10 or hex value of 0x0a
10.10.52.32 has a length of 11 or hex value of 0x0b
10.11.52.32 has a length of 11 or hex value of 0x0b
10.111.52.32 has a length of 12 or a hex value of 0x0c
192.168.100.10 has a length of 14 or a hex value of 0x0e

Hex Value of IP

ASCII to HEX of '1' = 31
ASCII to HEX of '0' = 30
ASCII to HEX of '.'  = 2E

10.10.10.10
31302e 31302e 31302e 3130

The Complete Option 43 Hex for IP 10.10.10.10 with ZD sub option (03) is  030b31302e31302e31302e3130

The Complete Option 43 Hex for IP 10.10.10.10 with vSZ sub option (06) is 
060b31302e31302e31302e3130

This is the coverstion method, Hope this Helps.

Regards,
Abilash PR.

unknown · Answer

It is the vendor controller identifier and HEX value of the IP address.
https://support.ruckuswireless.com/answers/000004456

unknown · Answer

It would be nice to know what calculation method is being used by Ruckus so that if this site is down/unavailable we can do it ourselves.