NAT problem with pppoe

[Reinhard Haller]

Hi,

I suspect pf is caching invalid outdated dynamic addresses. After this 
happens, all requests
sent from internal hosts are sent with the previous dynamic address as 
source address and
are ignored by our provider. Requests sent directly from our pf-box use 
the new dynamic
address as expected.

/etc/pf.conf

ext_if="tun0"
external_net="!192.168.0.0/16"

nat on $ext_if from !($ext_if) -> ($ext_if)

anchor portupgrade out on $ext_if
pass out on $ext_if from ($ext_if) to $external_net tagged FORWARD
pass quick proto { tcp, udp } from $dns_server to <dnsServer> port 
domain tag FORWARD

the anchor portupgrade is filled with the ppp-linkup script (DNS0/1)

pass quick inet proto udp from (tun0) to 212.18.3.5 port = domain keep 
state

Sending HUP to ppp does'nt eliminate the problem, pfctl -d/-e and a 
restart of the
internal server solve it.

The pf-box uses freebsd 7.0 stable, usermode-ppp is used to connect with 
the provider.

Any suggestions?

Thanks
Reinhard