I have a PIX 506E. The configuration is basic and mostly like it came out of the box.
The other day I wanted to add a static mapping to allow inbound access to a web server (port 80). I added a static statement, an access-list statement, and an access group statement. When I did that the inside computers could no longer access the internet. I removed all three statments and did a clear xlate so I could find out which statement caused the problem. I re-entered the static statement and it turns out that it was the static statment causing the problem.
I was using one external IP address for PAT and another to do the static mapping with. The static statement looked like:
static (inside,outside) 10.0.0.15 192.168.0.55 netmask 255.255.255.255.
I found this statement on one of the cisco support pages:
"If you specify an access-list command statement and bind it to an interface with the access-group command statement, by default, all traffic inbound to that interface is denied. You must explicitly permit traffic. Note that "inbound" in this context means traffic passing through the interface, rather than the more typical PIX Firewall usage of inbound meaning traffic passing from a lower security level interface to a higher security level interface."
In another document I found the following statement:
"By default, there are no access restrictions on outbound connections through the PIX. This means that if there is no ACL configured for the source interface, then, by default, the outbound connection will be allowed if there is a translation method configured. "
I am curious if both of these are telling me that I need to add two statements like:
access-list acl_outbound permit ip any any AND
access-group acl_outbound in interface inside.
I don't see why I would need to do this since the static statement alone killed the outbound connection. Or is it something else
Also (and unrelated to the above) what about the statement:
"IP addresses in the pool of global addresses specified with the global command require reverse DNS entries to ensure that all external network addresses are accessible through the PIX. [snip]. Without the PTR entries, sites can experience slow or intermittent Internet connectivity and FTP requests fail consistently."
Can someone explain that to me.
thanks
