On Fri, 9 Jan 1998, Eric C Wagner wrote:
> Under 1.2 whenever there was ip traffic pppd would dial out to the isp and
> connect. After 25 minutes of no user traffic the connection would be
> closed down. With 1.3 I get the complaint that active-filter can't be used
> due to incorrect iotcl's in the log and the modem never hangs up. So did
> the generic configuration change between 1.2 and 1.3 and if so what option
> should I add to enable active-filtering?

>From the pppd(8) manpage:
       active-filter filter-expression
                    .
                    .
                    .
              being  interpreted  by  the  shell.  This option is
              currently only available  under  NetBSD,  and  then
              only if both the kernel and pppd were compiled with
              PPP_FILTER defined.

So, you need to add "options PPP_FILTER" to your kernel configuration
file. Someone should mention this in the GENERIC kernel config file or
something; the i386 GENERIC has:
#options        PPP_FILTER      # Active filter support for PPP (requires bpf)