Problem with TCP 1433, conduits and ACLs...

["Wes Noonan" <mailinglists () wjnconsulting com>]

Had a strange problem last night doing a PIX upgrade. Here is the scenario:

2 PIX515E in failover configuration. Upgraded the PIXOS to 6.3(3) from
6.1(4). Installed new activation key for 3DES (they have UR license). The
next step was to convert a bunch of conduits and statics to ACLs.

The original statics were "open". IP x to IP y kind of stuff. We converted
them to port specific statics. The conduits were also converted to ACLs.
Seemed pretty straight forward. When we applied the changes, everything
seemed to be working except for one webserver. The server build the web
pages from a SQL database running on the internal network. The server would
not load any pages and displayed a custom error message that essentially
stated "I can't access the database". Every other system worked fine
however, and for the real kicker I could telnet from the webserver to TCP
1433 on the SQL server and get the SQL session to come up.

The original conduit/static was as follows:
static (inside,dmz) 172.16.11.134 172.16.4.134 netmask 255.255.255.255 0 0
conduit permit tcp host 172.16.11.134 eq 1433 host 172.16.8.101

The new ACL/static was as follows:
static (inside,dmz) tcp 172.16.11.134 1433 172.16.4.134 1433 netmask
255.255.255.255 0 0
access-list dmz_ingress_01 permit tcp host 172.16.8.101 host 172.16.11.134
eq 1433

In looking at the logs, I could see the hit count on the ACL increasing. I
could also see the sessions being created, but I never saw any data passing.
I added the "log" option to the ACL as well as putting an explicit "deny ip
any any log" entry and never saw anything that indicated why the system
wouldn't work. I was not running the sqlnet fixup on that port number.

I am pretty much at a loss for what the problem was. In the end we decided
to roll back the ACLs for the DMZ and put the old conduits back in place
with the new static statements. As soon as we did that, it started working
fine. Clearly there seems to be an issue with how the PIX is handling the
ACL traffic as opposed to the conduit traffic, but I can't see what that
might be. TIA.

Wes Noonan
281-208-8993
wnoonan () houston rr com
http://www.wjnconsulting.com 


_______________________________________________
firewall-wizards mailing list
firewall-wizards () honor icsalabs com
http://honor.icsalabs.com/mailman/listinfo/firewall-wizards