On Sat, Aug 26, 2006 at 11:29:54PM -0400, NetNeanderthal wrote:
> On 8/26/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> >For some reason, I'm not "getting it" when it comes to pf...  Two
> >things I can't figure out: (1) filtered vs blocked for some TCP
> >ports and (2) rules for tun0, my vpn interface.
> >
> >First, my /etc/pf.conf:
> >
> >    int_if = "vr1"
> >    ext_if = "vr0"
> >    vpn_if = "tun0"
> >    tcp_services = "{ 22 }"
> >    udp_services = "{ 1194 }"
> >    priv_nets = "{ 127.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12, 10.0.0.0/8 
> >    }"
> >    set block-policy return
> set block-policy drop
> 
> This will cause the default behaviour of your block statements to
> 'drop' the packet silently (aside from internal logging) rather than
> 'return' which quite literally returns an ICMP unreachable, which NMAP
> interprets as a 'filtered' port.

Actually, you got it the wrong way round - nmap assumes a port is
filtered when it gets no response.

> >Now, regarding (2), I'm trying to set up OpenVPN.  I've got a mostly
> >default setup (i.e. followed the openvpn HOWTO almost verbatim).  I
> >can establish the VPN tunnel, but cannot ping the obsd box.
> >
> >So, if I do a "tcpdump -n -e -ttt -i pflog0" while trying to ping
> >the obsd box from the vpn client, I see this:
> >
> >    Aug 26 21:08:49.371324 rule 4/(match) block in on tun0: \
> >    192.168.2.6 > 192.168.2.1: icmp: echo request (DF)
> >
> >How can I tell which rule is "rule 4"?
> Try using the 'label' keyword, re:
> block log all label "$nr - default deny"

Or pfctl -s.

                Joachim

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