Comments on: iPhone and Exchange – push and DNS

By: Gabe

Gabe — Thu, 21 Jan 2010 04:36:51 +0000

These dns solutions will only work if your router/firewall is configured to support NAT loopback. Some lower/mid-range consumer devices don’t support it at all.

By: Chris Abichandani

Chris Abichandani — Fri, 18 Dec 2009 16:40:11 +0000

@gregr, you are correct. I have a wildcard cert that I got from RapidSSL. They are only $199. So *.mydomain.com has been secured for quite some time. Wildcart certs NOW cost what REGULAR certs USED to cost! Totally worth it in my book.

http://www.rapidssl.com/index_ssl.htm

By: gregr

gregr — Thu, 03 Dec 2009 23:40:19 +0000

@Chris – sounds like a good idea! I might do that myself. The only downside that comes to mind is you’d need an SSL certificate for iphonemail.mydomain.com…

By: Chris Abichandani

Chris Abichandani — Thu, 03 Dec 2009 23:37:33 +0000

I had the exact same problem as the article author. His fix worked for me, but I modified it slightly to be able to continue to resolve internal names in my split-DNS infrastructure. My server is accessible at mail.mydomain.com. Externally that is 5.6.7.8, for example, but internally it is 1.2.3.4.

Push was working externally, but not internally over wifi.

To address the issue, which may be what MacIT was suggesting, I added an A record to my internal DNS pointing iphonemail.mydomain.com (a new name I just made up) to my external IP, 5.6.7.8 instead of the internal one. I added it externally as well.

Now, iphonemail.mydomain.com resolves to 5.6.7.8 both internally and externally, so push works inside the LAN or on the internet. The benefit here is that I can still access my internal servers on the iphone while connected to my lan.

As the author pointed out, this will only work for you if you can reach your external IP internally. I am using ISA Server 2006, if that helps.

As Debello encountered, you also of course have to be able to add A records.

I’m a happy camper now :)

By: Debello

Debello — Thu, 24 Sep 2009 20:06:03 +0000

Just found this article after fighting with my new Iphone for a bit. Was exactly the issue, we have different external/internal IPs and I was on wifi. To bad I can’t change our network setup and will have to go without wireless while in the office.

By: iPhone & ActiveSynch « technoDAVE

iPhone & ActiveSynch « technoDAVE — Sat, 08 Aug 2009 18:13:29 +0000

[...] this is not the case. Here’s a link to a workaround for internal WiFi use: Point the DNS servers for the iPhone’s internal Wi-Fi [...]

By: David

David — Tue, 28 Jul 2009 19:50:15 +0000

Thanks for the help. Worked perfectly.

By: Jamie

Jamie — Wed, 20 May 2009 14:21:35 +0000

I have an internal mail server

150.2.55.48 mail.domain.co.uk
externally it is
192.9.62.24 mail.domain.co.uk

from the external www, I can access my server via the web no problem, internally, my dns resolves mail.domain.co.uk as the external address and does not work.

How do I add an entry to the internal dns server to point to the internal address and not the external one?

Thanks

By: Sean

Sean — Wed, 18 Mar 2009 07:01:46 +0000

Question for Mac IT Solutions, how does this help and does he mean to do this on the primary DC or on the exchange server which is running OMA/Activesync?
I’ll give it a try though I can’t see how this will help anything, mail server was resolvable it’s just push email that’s not working.
I read on another forum that the reason that OMA push email works so well is down to the fact that exchange relies on the connections being slow between your iPhone and the server.
I’d be interested to know if push email works over wireless for any phones. I can sync my email well enough over the wireless it’s just the push notifications I’m not getting.
I honestly don’t see why it has to be an externally resolvable server IP address for this work properly. Very strange…
Anyway I’ve done what Mac IT solutions has suggested for now, maybe the Host A creates and authoritive answer for the iphone to go “oh I really am meant to be using this address not some external one”.
Anyway thanks for the info guys.

By: Daniel

Daniel — Tue, 03 Mar 2009 00:50:26 +0000

I had the same issue since I installed Exchange 07 and the external OWA address had changed. Once I figure out how to change that back to normal I should be ok, BUT: I followed the original suggestion about changing the DNS numbers. However, I did not use an “external” rather I used my internal router IP of 10.x.x.1, which already has the static DNS’s set up in the WAN settings.