Re: option 61

["Syed M. Irfan Ashraf" <[e-mail]>]

> The dhc-options-1533update-04.txt document states: 
> 
>    The client identifier MAY consist of type-value pairs similar to the
>    'htype'/'chaddr' fields defined in [3]. For instance, it MAY consist
>    of a hardware type and hardware address. In this case the type field
>    SHOULD be one of the ARP hardware types defined in STD2 [22].  A
>    hardware type of 0 (zero) should be used when the value field
>    contains an identifier other than a hardware address (e.g. a fully
>    qualified domain name).
> 
> It then diagrams the option to look like this:
> 
>    Code   Len   Type  Client-Identifier
>    +-----+-----+-----+-----+-----+---
>    |  61 |  n  |  t1 |  i1 |  i2 | ...
>    +-----+-----+-----+-----+-----+---
> 
> Is the "Type" field optional?  Is that what "MAY" in the first sentence
> above means?  If it is optional, then how does one tell when it is
> there and when it is not (i.e. when can I interpret that 3rd byte
> as a type field)?  Couldn't there by interoperability problems if
> one implementation assumes the type byte is there and another does not?


>From what memory serves me, previous discussions on the list concurred
that client-id would be used as an opaque string by all implementations.

The client might want to use a  type/val format or just any format
data in the client-id option.  The above recommendations for using defined
htypes or 0, applies only if it is using type/val format.

I treat client-id as a string with no semantics other than a unique
key into lease database. There is no way to tell if the client is
using type/val format.

-Irfan

> Edie