Re: cannot get mac address value starting by "00" with an snmp module

[dga <dam...@go...>]

Hello,

I would like to add more details to clarify the problem.

The 6 fields of mac address are returned to the agent under a string of 
6 chars: (let's say mac[6])

So for the following mac address : "00:48:65:6C:6C:6F" :

"00" => "NULL" = mac[0]

"48" => "H" = mac[1]

"65" => "e" = mac[2]

"6C" => "l" = mac[3]

"6C" => "l" = mac[4]

"6F" => "o" = mac[5]

it means we have : mac[6] = { '\0', 'H', 'e', 'l', 'l', 'o' , '\0'}

This string (mac[6]) is returned with an other parameter (size_t * 
var_len) to giving the size of the string.  Here the size is 6 of course.

But, when I get the corresponding oid value I get : "Hex-STRING: 00 00 
00 00 00 00"

It seems to be a bug ...

Best Regards,

Damien GARCIA


Le 11/01/2021 à 20:27, dga a écrit :
> Hello,
>
> I have written an snmp module to include additional interfaces in the 
> mib2 interface. However I face an issue with the field "ifPhysAddress" 
> (mac address) if the mac address of the interface starts by "00" 
> (example: "00:06:91:C6:B1:3F"). In that case I get "Hex-STRING: 00 00 
> 00 00 00 00" instead of getting  "Hex-STRING: 00 06 91 C6 B1 3F" . Is 
> it a bug ?
>
> I have no issue with my module if the mac address that does NOT start 
> by "00".
>
> There is also no issue get mac address starting by "00" for the 
> default interfaces of the snmp demon.
>
>
> May be someone has ever face the same issue ? Any help would be 
> greatly appreciated !
>
>
> Best Regards,
>
> Damien GARCIA
>
>