Configure ASA 5505 to allow CTIW on the SBS 2008

[schnitz629]

When using the connect to the internet wizard in SBS 2008 (CTIW) the server comes back with an error that it cannot communicate with the router.

Are there any settings that need to be configured in the ASA 5505 to allow communications with SBS 2008 using Exchange Server 2007?  I am using ASDM 5.2 at this time.

[mirober2]

Hello,

Do you have the DHCP server enabled on the ASA's inside interface? According to Microsoft's documentation, the CTIW first looks for a valid DHCP server to detect the router's/firewall's IP address:

http://blogs.technet.com/b/sbs/archive/2008/09/17/introducing-the-connect-to-the-internet-wizard-ctiw.aspx

SBS setup will attempt to detect an existing DHCP service. If DHCP is properly configured, we will also find the router.

If DHCP is not enabled on the ASA, you can enable it via the Configuration > Device Management > Management Access > DHCP > DHCP Server window in ASDM. You could also use a 3rd party DHCP server.

If a DHCP server is not available, the CTIW will only attempt to discover routers/firewalls in the 192.168.x.x/24 range. Therefore, if the ASA's inside interface has an IP address in a different subnet (and a DHCP server is not enabled), the CTIW will fail to find it:

If it doesn’t detect DHCP, it will attempt to detect the router primarily on 192.168.x.1 or 192.168.x.254.  It will not automatically detect routers in 172.x.x.x or 10.x.x.x networks.

Hope that helps.

-Mike

[schnitz629]

The current router is in the 172.26.x.x range and when DHCP is enabled the error is that there is another instance of DHCP on the domain (router ip address identified) that must be disabled before CTIW can finish.  When DHCP is disabled the error is unknown problem, contact microsoft.

Very frustrating.

[schnitz629]

Now after taking a closer look at the setup if have the following:

Public internet coming in through a Motorola Business Class Modem/Router/Firewall that has the Firewall disabled but DHCP and DNS enabled with the same IP address as the ASA (172.26.X.X)

Cisco ASA 5505 has both DHCP and DNS enabled also.  All ports needed for CTIW opened pointing to the SBS2008(172.26.X.X).

Have tried every combination of disabling these services on the non SBS components and still get either:

Unknown Error, Contact Microsoft.

Cannot Configure E-Mail, Re-Run this wizard. or

CTIW has encountered a problem, Re-Run this wizard.