Hello, folks.

I  was trying to set up a somewhat decent PPP dial-on-demand con-
figuration for serving a small LAN with NAT ("decent" means  that
it would not dial on any traffic, such as unnecessary DNS lookups
or unauthorized utilization).  I was (and still am)  using  -cur-
rent as of 1999/07/17.

The  problem is that I was not getting expected results from {ac-
tive,pass}-filter-{in,out} rules.  I  thought  it  was  something
with  the  syntax,  so I decided to validate the expressions with
tcpdump first, and noticed that it was misbehaving too.  The sym-
pots can be seen at the end of the message.

Does NAT conflicts with pppd/tcpdump/bpf in some way?  I tried it
with kernels configured with and without  IPv6,  so  I  discarded
this guy as the cause (maybe I wrong?).  Did anybody else experi-
ence such problem?

I  am sup'ing latest sources right now, but since CVS update logs
since last download did not list files that seem to be related to
this problem, I am uncertain if it will work.

Regards,
	Pappires

---------------------------------

lan-host% ping 146.164.70.2

...

nat-host% tcpdump -n -i ppp0
tcpdump: listening on ppp0
00:05:09.237507 146.164.70.2 > 146.164.64.56: icmp: echo reply
00:05:10.095413 146.164.64.56 > 146.164.70.2: icmp: echo request
00:05:10.232621 146.164.70.2 > 146.164.64.56: icmp: echo reply
00:05:11.095681 146.164.64.56 > 146.164.70.2: icmp: echo request
00:05:11.234355 146.164.70.2 > 146.164.64.56: icmp: echo reply
00:05:12.095918 146.164.64.56 > 146.164.70.2: icmp: echo request

nat-host% tcpdump -n -i ppp0 host 146.164.70.2
tcpdump: listening on ppp0

	NOTHING!

nat-host% tcpdump -n -i ne1 host 146.164.70.2
tcpdump: listening on ne1
00:08:52.859285 10.0.2.1 > 146.164.70.2: icmp: echo request
00:08:52.986219 146.164.70.2 > 10.0.2.1: icmp: echo reply
00:08:53.859565 10.0.2.1 > 146.164.70.2: icmp: echo request
00:08:54.008826 146.164.70.2 > 10.0.2.1: icmp: echo reply
00:08:54.859755 10.0.2.1 > 146.164.70.2: icmp: echo request
00:08:54.989151 146.164.70.2 > 10.0.2.1: icmp: echo reply