I am running a 2007 exchange environment, that has three CAS servers configured. Two of the CAS servers were installed over a year ago. The third CAS server was installed one week ago. Prior to the third CAS installation, free busy lookups were successful. The setup is as follows: Three Exchange 2007 front-end servers( FE1/FE2/FE3), two of the front-ends (FE1/FE2) are configured as CAS and Hub, the third (FE3) is configured as CAS-HUB- Mailbox. FE1/FE2 reside in datacenter1, FE3 reside in datacenter2. The FE1/FE2 are managed by one SAN certificate that has the following DNS names: webmail.group.com hg1.group.com hg2.group.com FE1.group.com FE2.group.com autodiscover.group.com The FE3 server is managed by one SAN certificate that has the following DNS names: webmail2.group.com FE3.group.com hg3.group.com Mailboxes that reside on FE3, use https://webmail2.group.com to access mailbox, and mailboxes that are managed by fe01/fe02 use https://webmail.group.com. Accessing mailbox using OWA and Outlookanywhere works without an issue. Problem: Mailboxes that are on FE3 are able to view freebusy for mailboxes that are managed by itself and FE1/ FE2. However, FE1/FE2 managed mailboxes are not able to view freebusy on FE3 mailboxes. This issue is experienced through Owa and OutlookAnywhere. When I run get-webservicesvirtualdirectory I receive the following: Server Name InternalUrl BasicAuthentication ExternalAuthenticationMethods ExternalUrl Identity InternalAuthenticationMethods InternalNLBBypassUrl FE3 EWS(Default Web Site) https://fe3.group.com/EWS/Exchange.asmx True {Ntlm, WindowsIntegrated, Basic} https://webmail2.group.com/EWS/Exchange.asmx fe3\EWS (Default Web Site) {Ntlm, WindowsIntegrated, Basic} https://fe3.group.com/ews/exchange.asmx FE1 EWS (Default Web Site) https://fe1.group.com/EWS/Exchange.asmx True {Basic, Ntlm, WindowsIntegrated} https://webmail.group.com/EWS/Exchange.asmx fe1\EWS (Default Web Site) {Basic, Ntlm, WindowsIntegrated} https://fe1.group.com/EWS/Exchange.asmx FE2 EWS (Default Web Site) https://fe2.group.com/EWS/Exchange.asmx True {Basic, Ntlm, WindowsIntegrated} https://webmail.group.com/EWS/Exchange.asmx fe2\EWS (Default Web Site) {Basic, Ntlm, WindowsIntegrated} https://fe2.group.com/EWS/Exchange.asmx When I run the test email configuration autoconfiguration against a fe3 mailbox I get the following: Protocol: Exchange RPC Server: fe3.group.com Login Name: migrate Availability Service URL: https://fe3.group.com/EWS/Exchange.asmx OOF URL: https://fe3.group.com/OAB/4afe.... Unified Message Service URL: https://fe3.group.com/UnifiedMessaging/Service.asmx Auth Package: unspecified Protocol: Exchange HTTP Server: webmail.group.com Login Name: migrate SSL: Yes Mutual Authentication: Yes Availability Service URL: https://webmail2.group.com/EWS/Exchange.asmx OOF URL: https://webmail2.group.com/EWS/Exchange.asmx OAB URL: https://webmail2.group.com/OAB/4afe... Unified Message Servivce URL: https://webmail.group.com/UnifiedMessaging/service.asmx Auth Package: NTLM Certificate Principle Name: msstd:webmail.group.com Could someone tell me what is needed to fix the free busy?

hi, If a user1 on FE1/FE2 datacenter ask to get the user3's free/busy information whose mailbox is on FE3 , free/busy request will be proxy to FE3. Now you can't get the FB, so i think your problem is your cas3(FE3). According to your post information, i think may be your request from FE1/FE2 is blocked.So first i recommend that you should check the firewall on your FE3. Second, each operation will be recorded in app log. So can you check the app log about the Availability Service on FE1/FE2/FE3. See if you can get more information. IIs log also will record it, so you can search EWS in your iis log to get some information about your issue. hope can help you thanks,CastinLu TechNet Community Support

hi, If a user1 on FE1/FE2 datacenter ask to get the user3's free/busy information whose mailbox is on FE3 , free/busy request will be proxy to FE3. Now you can't get the FB, so i think your problem is your cas3(FE3). According to your post information, i think may be your request from FE1/FE2 is blocked.So first i recommend that you should check the firewall on your FE3. Second, each operation will be recorded in app log. So can you check the app log about the Availability Service on FE1/FE2/FE3. See if you can get more information. IIs log also will record it, so you can search EWS in your iis log to get some information about your issue. hope can help you thanks,CastinLu TechNet Community Support

hi, any update? thanks,CastinLu TechNet Community Support