Mobile Outlook Users connecting to Exchange Problem

[HaierIT]

Good afternoon, we are expercing some problems after switching our internal IP scope. We moved from our previous ip scope of 90.*.*.*** to a new scope of 10.*.*.***.

The problem is with about only 15 mobile users that are not able to connect their Outlook 2003 client to our Exchange server without a VPN connection. Outlook with time-out after about 2-3 minutes of trying and say that Exchange server can not be located. These users before we able to connect their Outlook with no vpn. After we switch the IP Scope now these users must be on VPN and also host file pointing at our mail server to establish a connection.

I do not know how changing our Internal IP scope will affect mobile users. Does anyone know what can possibily be causing this issue? The majority of our users are all working fine with their outlook. I do not know if its a DNS or an ISP issue, or something else.

thank you in advance.

 

[58sniper]

Did you update your firewall to reflect the new internal IP address of Exchange?

Pat Richard
Microsoft Exchange MVP
Contributing author The Complete Reference: Microsoft Exchange Server 2007

 

[HaierIT]

Hi 58sniper, yes we updated our Firewall. Its only about 15 out off +200 clients so it's not everyone.

Do you know why changing our Internal IP Scope effect the connecton of Outlook clients remotly? When clients connect without the vpn, it has noting to do with the internal network or am i missing something.

 

[Ogi]

You don't have an address configured in your HOSTS file on those PC's pointing to the old server address?

Carl.

 

[HaierIT]

We do not have a host file pointing to the old server.

We even tried updating the host file to point to the new server but Outlook still does not connect. We can ping the Exchange servers external address from the outside but can not connect.

I did notice that all users execpt one having this problem is under Comcast. The users were able to connect before without the VPN but now they can't. I am not sure if Comcast started blocking certain traffic. What are you thoughts on that? Is it even worth calling Comcast because I am sure they will give me the run-around.