dhcpcd-discuss

Hi Roy,

On Thu, Apr 26, 2018 at 9:33 AM, Roy Marples <roy@xxxxxxxxxxxx> wrote:
> Hi Mattie, sorry for the late reply
>
> On 23/04/2018 17:43, Mattieu Baptiste wrote:
>>
>> Yes, you're right. It doesn't make a difference.
>> Now, I can't see a reason why the server doesn't reply...
>> The three important options my ISP requires are precisely the same
>> between a request sent by the official modem and a request sent by
>> dhcpcd.
>> There are minor differences on other options, but I don't see what
>> would be the reason it fails.
>> What comes to mind...
>> - with dibbler, we need to set the "auth" option twice; otherwise it
>> doesn't work. Maybe the server doesn't like the options order in the
>> packet?
>> - the official modem and dibbler both requests the "auth" option in
>> the "option request" option, whereas dhcpcd don't. Maybe I need to
>> send that?
>> I'm a bit desperate on what's the problem of my ISP's crappy DHCP
>> server...
>>
>
> The attached patch should work.
> I'm not in a position to test it yet, maybe you could?

I spent a lot of time since a few days trying to modify dhcpcd's
source code with these kind of changes:
- changing the values of different options to try to mimic the original request,
- changing the order of the options.

The only time I managed to get a reply from the server is when the
authentication option is somewhere before the first ~160 bytes ; ie
not the last option of the request.

This is totally silly. Seems the server in question is this beast:
https://infoproducts.alcatel-lucent.com/html/0_add-h-f/93-0267-HTML/7X50_Advanced_Configuration_Guide/ESMv6_IPoE_dual_stack_hosts.html#

-- 
Mattieu Baptiste
"/earth is 102% full ... please delete anyone you can."