I was speaking with a colleague from a previous job, and they were
testing out Exchange 2013 in their lab environment, and were not having
much success with even getting it installed. Being the curious cat that I
am, I thought I'd help them out.
Long story short:
don't uncheck IPv6 on the server that is running Exchange 2013. You will
have problems. Microsoft themselves say that they neither test nor
support a configuration in which IPv6 is disabled in the NIC
The problem at the moment is that not many
ISPs are IPv6 compliant, and not many organizations have the resources
or time to properly implement IPv6 services on their network. As in my
colleague's case, IPv6 is enabled by default in current versions of
Windows, but without IPv6 DHCP or auto configuration, the address that
gets assigned is not always very useful, and can cause communications
issues by itself. Even worse, most Windows Servers will try to register
that IPv6 address within DNS as an AAAA record.
result, let's say that theoretically you have a single exchange server
(exmbx01 on Server 2008 R2), a single domain controller that also runs
DNS and DHCP (IPv4) (dc01 also on 2008 R2), and your client workstation
(desktop01 running Windows 7). You try to ping exmbx01 from your
workstation, and more than likely, you will be pinging an IPv6 address
that starts with fe80, and your pings will fail. This happens because
most likely your Exchange server registered its IPv6 address in DNS, and
all Windows clients that are Windows 7 or Windows 8 will try to fetch
an AAAA record first. In some cases, it might still work, but what if
your Exchange server and client are separated by a site-to-site VPN or
MPLS that is tunneling IPv4 traffic?
A lot of times,
lazy admins will simply disable IPv6 on the servers, pat themselves on
the back, and call it a day because everything seems to be working.
Exchange Server 2013, the latest and greatest. While the above
"solution" will basically work for the majority of organizations, it's
not supported at all in the latest revision of Exchange Server. In fact,
Exchange will simply fail to install if IPv6 adapters are disabled.
Furthermore, an incomplete install of Exchange 2013 in this manner will
have other, more serious problems, as outlined by this post:
The correct solution is either to keep IPv6 enabled, or to selectively disable it via the registry.
The proper way to do it is outlined here: http://support.microsoft.com/kb/929852
Labels: Exchange 2013, IPv6