Disclaimer: This is not an official KB, These are just notes that has been collected or communicated and open available on the internet…
if you have been reading my blogs and following me online you will note that I am a fan of disabling IPv6 and I am always recommending disabling it on the Exchange Server as well on DCs. I have seen service starting issues and communication issues that was resolved but disabling IPv6.
I have seen a discussion around IPv6 were with other fellow MVPs, and Thanks to Nicolas Blank for point to a very important point.
quoting Nicolas:IPv6 is a bit more than supported, it’s part of the CEC, just like PowerShell and GPO manageability is: For those of us who don’t know, CEC is the Common Engineering Criteria and I’ll paste from the CEC link: All Microsoft server products are required to comply with a set of engineering requirements as part of the Microsoft Common Engineering Criteria (CEC) program. The goal of the CEC program is to reduce the overall total cost of ownership (TCO) through improved integration, manageability, security, reliability, and other critical infrastructure attributes that are expected by our customers. THE IPv6 bits are explicitly stipulated here: http://www.microsoft.com/cec/en/us/cec-overview.aspx#data-ipv6 Internet Protocol version 6 support IPv6 solves numerous connectivity issues and issues that are associated with IPv4 address depletion. All Microsoft server products are required to support both IPv6 and IPv4. In addition, all server products are required to be configurable to run in dual-stack (IPv4 and IPv6) or IPv6-only modes. Exchange 2010 scores a G in the IPv6 scorecard, which means “The server product complied with this requirement” http://www.microsoft.com/CEC/en/us/cec-scorecards.aspx?display=tech under “Data Center and Enterprise Readiness” That means Exchange is MEANT to work with IPv6, if some bits need ipv6 disabled in order to get things to work
That means that in order to make your Windows that hosts Exchange CEC compatible then you will need to make sure that IPv6 is enabled on your server.
however note that there is no harm in disabling IPv6 (keep in mind that UM role is not compatible with IPv6) so no harm in disabling it but Exchange was designed and tested with IPv6 in mind and against IPv6.
I have to admit that I have been disabling IPv6 on all of our servers, and that was my recommendations but that should be changed but note:
– Exchange 2010 is designed to work with IPv6 and tested against IPv6.
– To comply against the CEC you will have IPv6 enabled on your servers.
– UM role is not compatible with IPv6 so you will have to disable IPv6.
– To disable IPv6 on a given server you MUST not disable it bu un-checking the IPv6 check box on the TCP/IP properties and you must disable it from the registry.
again the above are just the findings until now for the IPv6/Exchange topic. I will update you if I have any other news in this specific topic.