Setting Up Free Busy Interop with Exchange 2007

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3. Setting Up Free Busy Interop with Exchange 2007

Setting up Free Busy Interop with Exchange 2007

 - This is archive documentation, which means it is not supported or valid for recent versions of Zimbra Collaboration.

 - This article is a Work in Progress, and may be unfinished or missing sections.

Note:

• These instructions assume that MS Exchange 2007 and Zimbra Collaboration Suite have been installed using the "DEFAULT" configurations. Modify wherever necessary according to your target system’s configurations/settings.
• MS Exchange 2007 System obtains Free/Busy information by using Availability Service instead of Public Folder which is used by Exchange 2003 (The Availability Service obtains the user’s Free/Busy information from its mailbox directly). However Zimbra Collaboration Suite’s interoperability with MS Exchange System is based on the “legacyExchangeDN” attribute which assumes that the Free/Busy information is published into the public folder using WebDAV. If your MS Exchange 2007 System does not have a Free/Busy folder then you can create a new one using the following Exchange 2007 Management Shell (EMS) Command:

[PS] C:\>New-Publicfolder -name "EX:/o=First Organization/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)" –path 
"\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY"

• You also need to ensure that the Exchange 2007 CAS server is forwarding WebDAV service requests to the backend Exchange 2007 Mailbox server.

I. Exchange Free/Busy Lookup from Zimbra

On the Exchange 2007 System:

[1]. Create a Service Account on MS Exchange 2007. Name it "zimbra".

• You may do this by using the following EMS Command:

[PS] C:\>$password = Read-Host "Enter password" -AsSecureString
 
[PS] C:\> New-Mailbox -Name 'USER_NAME' -Alias 'USER_ALIAS' -OrganizationalUnit '<OrganizationalUnitIdParameter>’
 -UserPrincipalName 'USER_ALIAS@EXCHANGE_DOMAIN' -SamAccountName 'USER_ALIAS' -FirstName 'USER_FIRST_NAME' -
Initials 'USER_INITIALS' -LastName 'USER_LAST_NAME' –Password $password -ResetPasswordOnNextLogon $false -Database
 '<DatabaseIdParameter>' 

Example: 
[PS] C:\>$password = Read-Host "Enter password" –AsSecureString Enter password: ******

[PS] C:\>New-Mailbox -Name 'zimbra' -Alias 'zimbra' -OrganizationalUnit 'exchange2k7.local/Users' -UserPrincipalName
 'zimbra@exchange2k7.local' -SamAccountName 'zimbra' -FirstName 'zimbra' -Initials '' -LastName '' 
-Password$password -ResetPasswordOnNextLogon $false -Database 'win2k3r2\First Storage Group\Mailbox Database'

• Alternatively you can first create an Active Directory user object "zimbra" (in the "USERS" container) and then assign a mailbox on the Exchange 2007 System by using the following EMS Command:

[PS] C:\> Enable-Mailbox -Identity '< OrganizationalUnitIdParameter>/USER_NAME' -Alias ' USER_ALIAS' -Database
 '<DatabaseIdParameter>’

Example:
[PS] C:\>Enable-Mailbox -Identity 'exchange2k7.local/Users/zimbra' -Alias 'zimbra' -Database 'win2k3r2\First Storage
 Group\Mailbox Database'

If you are more comfortable with AD/Exchange GUI interface then use the same to complete either of the above mentioned steps according to your requirement.

[2]. Use the ADSIEDIT tools on the AD/Exchange server to find out the legacyExchangeDN attribute of the Service Account. You would need this while configuring the settings on the Zimbra System. You may find out the legacyExchangeDN by following this method.

1. On the AD/Exchange Server, click START > Run > Type adsiedit.msc
2. Select your Domain’s Node and expand the tree until you reach the node “CN=Users”. Now expand this node to find the container “CN=<Your Service Account Name>” (e.g. “CN=zimbra”).
3. Right click the container described in [2.] and select “Properties” to open the properties screen.
4. Browse the attributes to find the legacyExchangeDN attribute. Click on “Edit”.
5. From the “String Attribute Editor” window obtain (copy) the part of the string appearing before “/cn=Recipients/cn=<Your Service Account Name>”. The copied string should look something like “/o=First Organization/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)”. Keep this string safe; we will use it further down to configure the Zimbra System.
6. Close all the windows, keep in mind not to modify any attribute values appearing in the ADSIEDIT Interface.

On the Zimbra System:

[3]. Modify the Zimbra System’s config using the “zmprov modifyConfig” to use the settings from the MS Exchange 2007 System.

• Exchange Service Account Credentials:

zmprov mcf zimbraFreebusyExchangeAuthUsername [Exchange 2007 Service Account Name]
zmprov mcf zimbraFreebusyExchangeAuthPassword [Exchange 2007 Service Account Password]

Example:
[zimbra@zimbra /]$ zmprov mcf zimbraFreebusyExchangeAuthUsername zimbra 
[zimbra@zimbra /]$ zmprov mcf zimbraFreebusyExchangeAuthPassword z1mbr4

• Exchange Authentication Schema:

zmprov mcf zimbraFreebusyExchangeAuthScheme [basic or form]

Example:
[zimbra@zimbra /]$ zmprov mcf zimbraFreebusyExchangeAuthScheme basic

Note: The Exchange Auth Schema is either “basic” or “form”. When “basic”, the authentication to the Exchange 2007 System happen using HTTP basic authentication. When “form”, the authentication to Exchange 2007 System happen using HTML form based authentication.

• URL to Exchange 2007 CAS server:

zmprov mcf zimbraFreebusyExchangeURL https://[URL of CAS server]

Example:
[zimbra@zimbra /]$ zmprov mcf zimbraFreebusyExchangeURL https://win2k3r2.exchange2k7.local

• Exchange legacyExchangeDN attribute:

zmprov mcf zimbraFreebusyExchangeUserOrg “/o=First Organization/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)”

Example:
[zimbra@zimbra /]$ zmprov mcf zimbraFreebusyExchangeUserOrg “/o=First Organization/ou=Exchange Administrative Group
 (FYDIBOHF23SPDLT)”

II. Zimbra Free/Busy Lookup from Exchange

On the Exchange 2007 System:

Ensure that the Service Account has been created on the Exchange 2007 System as per description provided in section I. [1]. above.

[1]. Allow the Service Account ("zimbra") to update the Exchange Free-Busy folder. You may do this by using the following EMS Command:

[PS] C:\> add-publicfolderclientpermission -identity "\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY\EX:/o=First 
Organization/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)" –user <Service_Account_USER_NAME> 
-accessrights owner

Example:
[PS] C:\> add-publicfolderclientpermission -identity "\NON_IPM_SUBTREE\SCHEDULE+ FREE 
BUSY\EX:/o=First Organization/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)" 
-user zimbra -accessrights owner

[2]. Make Exchange 2007 aware of the presence of “Public Folders” in the Zimbra domain. You may do this by using the following EMS Command:

[PS] C:\> Add-AvailabilityAddressSpace -forestname <ZIMBRA SYSTEMS's FQDN> 
-accessmethod publicfolder

Example:
[PS] C:\>Add-AvailabilityAddressSpace -forestname zimbra.local -accessmethod publicfolder

[3]. Create a "Zimbra" OU in Active Directory. Make sure all your Zimbra users are created as “Exchange 2007 Mail Contact Objects” in this OU. As a BEST PRACTICE, to reduce the risk of a collision in namespace a suffix can be added to denote a Zimbra account (i.e. “_zimbra”). Also for each of the mail-contact objects that you create here, set one of the available/not-set “Exchange Extension Attributes (extensionAttribute1 to extensionAttribute15)” to an optional tag (say “_zimbra”). You may use ADSIEDIT utility to set this attribute. Also ensure that the same extension attribute is set for all the zimbra contact objects.

• You may create a mail-enable user by using the following EMS Command:

[PS] C:\> New-MailContact -ExternalEmailAddress 'SMTP:<Email Address of the Zimbra User on the Zimbra System>' -Name 
'<Zimbra User’s corresponding Contact Object Name on the AD>' -Alias '<Zimbra User’s 
corresponding Alias on the AD>' -OrganizationalUnit '<EXCHANGE 2007 FQDN>/<Zimbra OU on AD>' 
-FirstName 'CONTACT_FIRST_NAME' -Initials 'CONTACT_INITIALS' -LastName 'CONTACT_LAST_NAME' 

Example:
New-MailContact -ExternalEmailAddress 'SMTP:testuser1@zimbra.local' -Name 'testuser1_zimbra' 
-Alias 'testuser1_zimbra' -OrganizationalUnit 'exchange2k7.local/Zimbra' -FirstName 
'testuser1_zimbra' -Initials '' -LastName ''   

• Alternatively you can first create an Active Directory contact object as "USER_Zimbra" (in the "Zimbra" OU) and then mail-enable that contact on the Exchange 2007 System by using the following EMS Command:

[PS] C:\> Enable-MailContact -Identity '<EXCHANGE 2007 FQDN>/<Zimbra OU on AD>/<Zimbra 
User’s corresponding Contact Object Name on the AD>' -ExternalEmailAddress 'SMTP:<Email Address of 
the Zimbra User on the Zimbra System>' -Alias 'Zimbra User’s corresponding Alias on the AD' 

Example:
[PS] C:\>Enable-MailContact -Identity 'exchange2k7.local/Zimbra/testuser2_zimbra' -ExternalEmailAddress 
'SMTP:testuser2@zimbra.local' -Alias 'testuser2_zimbra'

On the Zimbra System:

[4]. Configure the zimbra user account to push its Free/Busy status to the Exchange 2007 System.

zmprov ma <Zimbra Account> zimbraForeignPrincipal ad: <Exchange mail contact>

Example:
[zimbra@zimbra /]$ zmprov ma testuser1@zimbra.local zimbraForeignPrincipal ad:testuser1_zimbra 

III. Merge the GALs of Exchange and Zimbra Domains:

On the Exchange 2007 System:

On the Exchange 2007 System no further work needs to be done since all Zimbra accounts would now be appearing as a mail contact in the Exchange 2007 GAL.

On the Zimbra System

Modify the Zimbra Domain’s config using the “zmprov modifyDomain” to get a unified view of the GAL (consisting of GAL users from both Exchange 2007 System and Zimbra System).

zmprov md <Zimbra Domain> zimbraGalMode both
zmprov md <Zimbra Domain> zimbraGalMaxResults <Integer Value>
zmprov md <Zimbra Domain> zimbraGalLdapURL ldap://<FQDN of the Active Directory>:3268
zmprov md <Zimbra Domain> zimbraGalLdapFilter (&(|(cn=*%s*)(sn=*%s*)(gn=*%s*)(mail=*%s*))
(! (msExchHideFromAddressLists=TRUE))(! (<Exchange Extension Attribute Number>=<Optional 
Tag Set on Exchange 2007 System >))(mailNickname=*)(|(objectClass=user)
(objectClass=contact)(objectClass=msExchSystemMailbox)''(objectClass=msExchDynamicDistributionList)
(objectClass=group)(objectClass=publicFolder)))
zmprov md <Zimbra Domain> zimbraGalAutoCompleteLdapFilter adAutoComplete
zmprov md <Zimbra Domain> zimbraGalLdapSearchBase <AD base DN>
zmprov md <Zimbra Domain> zimbraGalLdapBindDn <UserPrincipalName of the Zimbra Service Account created on the AD>
zmprov md <Zimbra Domain> zimbraGalLdapBindPassword <Password of the Zimbra Service Account>  

Example:
[zimbra@zimbra /]$ zmprov md zimbra.local zimbraGalMode both
[zimbra@zimbra /]$ zmprov md zimbra.local zimbraGalMaxResults 100
[zimbra@zimbra /]$ zmprov md zimbra.local zimbraGalLdapURL ldap://win2k3r2.exchange2k7.local:3268''
[zimbra@zimbra /]$ zmprov md zimbra.local zimbraGalLdapFilter (&(|(cn=*%s*)(sn=*%s*)(gn=*%s*)
(mail=*%s*))(! (msExchHideFromAddressLists=TRUE))(! (extensionAttribute1=_zimbra))(mailNickname=*)
(|(objectClass=user)(objectClass=contact)(objectClass=msExchSystemMailbox)(objectClass=msExchDynamic
DistributionList)(objectClass=group)(objectClass=publicFolder)))
[zimbra@zimbra /]$ zmprov md zimbra.local zimbraGalAutoCompleteLdapFilter adAutoComplete
[zimbra@zimbra /]$ zmprov md zimbra.local zimbraGalLdapSearchBase dc=exchange2k7,dc=local
[zimbra@zimbra /]$ zmprov md zimbra.local zimbraGalLdapBindDn administrator@exchange2k7.local
[zimbra@zimbra /]$ zmprov md zimbra.local zimbraGalLdapBindPassword z1mbr4

Troubleshooting

See http://wiki.zimbra.com/index.php?title=Troubleshooting_Exchange_Freebusy_Interop