Lessons Learned - Cisco ASA 5505 and TCP request discarded
Hi there, Last week, we set up a Cisco ASA 5505 firewall in one of our customers' LAN. It should replace the ISA 2000 firewall over there, because we need to create a site-to-site tunnel to a PIX 515E on a remote location. All went fine with this ASA 5505, except that it would not pass any traffic from the internet to the LAN. From the inside out, all was OK. From the outside in, nothing would pass the firewall. The relevant config lines were as follows: static (inside,outside) tcp w.x.y.z 25 10.10.10.10 25 netmask 255.255.255.255 access-list outside01 permit tcp any host w.x.y.z eq 25 access-group outside01 in interface outside So, here we redirect all SMTP traffic on public interface with IP w.x.y.z to private host 10.10.10.10. Nothing much would happen. Internally, the SMTP host was listening, of course. From outside, the interface with IP w.x.y.z was pingable, of course. From the outside, configuring the ASA with SSH or HTTPS went fine. (So, traffic TO the
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