>>         at this moment noone updates max_linkhdr.  i guess it has to be
>>         updated on interface attachments.
>>         but i'm reluctant to making the change since by doing so we can
>>         overflow some assumptions on MHLEN.  any comments?
>>         (things like MHLEN > max_linkhdr + sizeof(ip) + sizeof(tcp))
>It's updated in uipc_domain.c:
>         if (max_linkhdr < 16)           /* XXX */
>                 max_linkhdr = 16;

	correct, sorry i did not count it to "update" - it looked like
	"initialize" to me.

>It should be also be updated when doing if_attach but
>currently isn't.

	yes, this is the issue i'm seeing.

itojun