Our remote users access the network via anyconnect on a Cisco ASA 55xx with internet connection dedicated only for vpn access. We have another internet connection with stonegate firewall used for all other corporate internet access. When users connect via the anyconnect VPN, email stops flowing, when they disconnect they start receiving emails. I have confirmed that when connected the VPN pool ip address have ip connectivity to the internal exchange servers, also accessing OWA when using VPN, they receive and send emails.
My question is why we are unable to send or receive emails on mobile devices (iphone) using activesync?
Might be that is the design issue with apple ios devices. So all you need is to enable the split-tunnel for the anyconnect connection to make it work..... because the active-sync traffic should not get in to tunnel, which will not work. In android it wont be a big cause.
Here’s the catch, in order for ActiveSync to work, you must first expose your OWA to the internet. ActiveSync basically connects via HTTP to your exchange OWA in order to fetch email. If you are connecting over a Cisco VPN (ipsec or anyconnect), pushed notifications will NOT work (however polled email will). Cisco blames Apple for their bad implementation of ActiveSync.
“Push email notifications do not work via VPN because of Apple iOS constraints. However, one can use AnyConnect in parallel with externally accessible ActiveSync connections, which the tunnel policy can exclude from the session.”
The last sentence there basically means other applications that support the push feature will work under the Cisco VPN, just not email. So please use our VPN concurrently with ActiveSync and OWA exposed to the internet. I’m inclined to think Apple Engineers need some spanking here.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...