Dhcp option 43 alcatel 6860E with wlc cisco

[javierlodu]

Hello everyone!!!
I have a dhcp server in my switch 6860E and a WLC cisco is connected, the APs need the option 43 for find the WLC’s address, i send the ip address of WLC in HEX format with option vendor in my dhcp pool, the value that the AP receive is ASCII, i tested with a dhcp server Cisco and the value that AP receive is HEX and Work fine!! I tested to send ASCII values, HEX values from my switch Alcatel but do not work, the ap’s keep on receiving ASCII


Alcatel 6860E. AP cisco Work?
Ip address HEX format. —————->ASCII value No

Switch cisco AP cisco
Ip address HEX format——————->HEX value Yes

can you help me please?

[silvio]

Everytime when you change the settings within the dhcpd.conf-file you have to use the command dhcp-server restart.
Did you use it?
If yes and the wrong option format will already be sent, you can check with wireshark (port mirror or port monitoring) the options within your dhcp-offers.
best regards
Silvio

[javierlodu]

Hi Silvio, thank you very much for the support
- yeah every time that i have changes use dhcp-server restart and dhcp-server enable
I checked with wireshark in dhcp ack
With dhcp-server alcatel i send f104.ac10.01fd and receive: 663130342e616331302e30313034
I test with a switch cisco
With dhcp-server cisco i send f104.ac10.01fd and receive f104.ac10.01fd

f104.ac10.01fd Is the ip address of wlc in HEX

I checked manual for the option 43 vendor-specific: option vendor-specific vspinfo where vspinfo is a hexadecimal text.
I need that dhcp-server alcatel deliver the option 43 value in HEX format
I dont know how upload images with wireshark’s capture
Thank you very much!!!

[javierlodu]

yeah, every time that i have changes use dhcp-server restart and dhcp-server enable
i attachment the wireshark's capture
i send the option 43 with the command option vendor-specific in HEX format but the ap receive ASCII value

[silvio]

is f104.ac10.01fd an IPv4 address?
I have found an successfull example for IP 10.1.20.10

Vendor-specific = Opt.43
0x40 = Suboption 64 0x04 = Länge 4 Byte
0A 01 14 0A = 10.1.20.10

option vendor-specific 40 04 0A 01 14 0A;

regards
Silvio

[javierlodu]

Hi Silvio, thank you for your support
i am sorry, f1 is the vendor Cisco, 04 is the length and ac10.01fd is de ip address.
the ip address is 172.16.1.253
i tested
option vendor-specific 40 04 ac 10 01 fd;
option vendor-specific f1 04 ac 10 01 fd;
option vendor-specific f1:04:ac:10:01:fd;
option vendor-specific f1:04:ac:10:01:fd:ff;
option vendor-specific [f104ac1001fd]..... With this command in wireshark the value is the same f104ac1001fd
then i added dots
option vendor-specific [f104.ac10.01fd].... but with this command in wireshark the value is "f104", i think that the dot is stop signal.
with all these commands none worked
can you help me please?

[silvio]

Hi,
I have now searched a lot....
The integrated DHCP is equiv. to Lucent QIP DHCP Server .... so you can find examle at the end of https://www.cisco.com/c/en/us/support/d ... 43-00.html

So I think you are correct with
option vendor-specific [f104ac1001fd];

0xf1 (241) is the vendorspecific option for Cisco (alcatel uses 0x40=64). Next is lenght 4 Byte. So with dots you have to increase this length value. But I think you don't need the dots.... (because in your cisco-example from the first post there is a length of 4 too - have you checked this with wireshark? )

Than I have seen an example where after every byte is a space:
option vendor-specific f1 04 ac 10 01 fd;

One of this has to work (you have tested already).

Also I have found, that within AOS 8.4.1.R03 there was an mistake with option 43 This is fixed in 8.5...

I hope you will found the solution ....
regards
Silvio