UAG registers ISATAP addresses and causes internal connectivity issues RRS feed

  • Question

  • I have a fully working DirectAccess implementation using UAG. The problem I have is with some internal servers communicating with each other, specifically a pair of Exchange Mailbox servers in a DAG.

    The Exchange Management console reports the mailboxes as 'Service Down' after a long delay. If I remove all the IPv6 addresses from DNS, clear the cache and do ipconfig /flushdns on the mailbox servers full communication is restored.

    Why are these servers having problems communicating with each other using the ISATAP registered address?

    Monday, March 21, 2011 6:04 AM

All replies

  • Hi Amigo. ISATAP is a way to route between IPv6 subnets when there is no IPv6 routers in place. If your Exchange servers have IPv6 addresses from differente subnets and there is no IPv6 router then they will try to communicate to each other through the ISATAP router. UAG will not be able to route that communication and then it will fail.


    // Raúl - I love this game
    Tuesday, March 22, 2011 12:05 PM