Link to home
Start Free TrialLog in
Avatar of piersk
piersk

asked on

What ports need to be open at the remote site to access OWA?

I know that port 80 needs to be open on my local firewall, but what ports need to be open on a remote site firewall for someone to be able to access OWA from there?

I was always under the impression that as long as the remote site had web access (and of course my firewall allowed it), then anyone at that remote site should be able to access OWA remotely.
Avatar of bwinzenz
bwinzenz

You are correct.  As long as the remote site can access the Internet (all http traffic uses port 80), then as long as your firewall has port 80 inbound open to the OWA server, they should be able to access it.  There really isn't much more to it than that.  If you think about it, OWA is just another website.

If you want to secure OWA, you would want to use SSL (https) and obtain a certificate from an online certificate authority (such as Thawte).

Ben
Avatar of piersk

ASKER

Apparently (having spoken to the support team at the remote location) there are other ports that need to be opened.

I probably should have explained myself a bit better. My colleague can access the site. He can log in and gets the icons on the left and the top, but nothing in the central, main part of the screen. I need to know the ports that need to be unblocked for this to work.
After looking at this again, it appears that the remote client will use a high port locally (1024+) and it connects to port 80 of the OWA server.  However, the outbound connection on the client should occur over port 80.  The local port that the client uses should not matter one bit.

Have you tested logging on to OWA locally on your LAN?  Does that produce different results?  Have you installed URLScan or the IIS Lockdown Tool on the OWA server?  Both of those are known to cause problems with OWA unless they have been specifically tuned for Exchange/OWA.

Ben
Avatar of piersk

ASKER

I havent installed URLScan or IIS Lockdown.

My colleague can access OWA when on dial up from the same workstation, just not when he is on the network (please bear in mind that he is doing some consultancy for another company and is at their offices), so I am trying to fix his for THEIR network guys. I know for a fact that its something to do with their firewall, but they have no idea what port needs to be unblocked, so I am doing the work for them...

I'm not bitter ;-)
Tell ya what.  I'm gonna set up my laptop in our DMZ (to simulate being on the Internet coming in), and I'll run a packet sniffer showing me all traffic from my laptop to my OWA server.  I'll post back the results in a few.  I honestly don't think it is a port issue.  It could be something *else* causing the problem, but it shouldn't be a port issue.

Ben
ASKER CERTIFIED SOLUTION
Avatar of bwinzenz
bwinzenz

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of piersk

ASKER

Not abandoned, just forgotten (sorry).

Spoke to the IT people their end (having seen bwinzenz's answer) and they have their network set up so that it would allow use of OWA 2k3, but I don't think they really had much of a clue since they didn't know how to change it to allow access for OWA2000. Such is life