Don't know what are you trying to see here, but what that rules does is
simple passing the traffic on any interface to your $front_smtp4 hosts
on port 25, with synproxy.
If you trying to forward traffic from the firewall to your $fornt_smtp4
servers, you are missing stuff.
https://www.openbsd.org/faq/pf/rdr.html
Rosen
Lyndon Nerenberg (VE7TFX/VE6BBM) wrote on 11/10/2021 14:41:
I'm trying to get synproxy working on a firewall, using the following
rule:
pass quick proto tcp from any to $front_smtp4 port 25 synproxy state
The firewall accepts the connection on the outside interface, but
I don't see (tcpdump) any attempt to complete the connectiom on the
inside interface. The state table shows a pair of entries with state
PROXY:SRC and DST:PROXY which line up with the connection, but all I
get it dead air.
This seems like it should 'just work'. Is there something obvious
I'm missing? I can give more detailed info (pf rules, ifconfig)
offline for anyone interested in helping out.
Thanks!
--lyndon
