Upgraded to ISA Firewalls, Issues with loopback and .NET debugging
Posted on 2003-12-04
We just upgraded to ISA Firewalls. Here's the network config:
Server: ISASERVER (Windows 2003 Server running ISA) / 2 NICs
External IP: 10.1.128.11 (gets translated to public internet IP through router in front of it)
Internal IP: 192.168.1.6
Server: PDC (Windows 2003 Server running ISA) / 2 NICs
External IP: 10.1.128.11
Internal IP: 192.168.1.4
(This server functions as domain controller, DNS, WINS, and mail server as well as a separate firewall for our developers -- the rest of the end-users go through the ISASERVER firewall, and yes I'm aware of the security involved in running ISA on domain controller, so there is a Cisco PIX in front of this server as well.)
Server: RUFUS (Windows 2003 Server) / 1 NIC - This is our web server running ASP.NET & SQL 2000.
Internal IP: 192.168.1.3
Gateway: 192.168.1.6 (ISASERVER Internal NIC)
My Workstation: Windows XP
Gateway: 192.168.1.4 (PDC Internal NIC)
Now, the question...
I have internal network DNS entries for "sql.mydomain.com" pointing to 192.168.1.3. In our web applications we always use "sql.mydomain.com" for the SQL server address. This worked wonderfully until we installed the ISA servers.
Now, the applications running on RUFUS reports that they cannot find the SQL server. nslookup says it resolves fine (192.168.1.3) but for some reason RUFUS will not loopback to itself when connecting.
I changed the DNS entry for "sql.mydomain.com" to 127.0.0.1 in Active Directory DNS, and now RUFUS is fine. Why the loopback issue and how to resolve?
Also, since the change to ISA, my Visual Studio .NET will not debug ASP.NET applications (getting "please reinstall remote debugging" error message -- not sure if this is related to the above problem!)