Network diagnostics for the O365 Dedicated/ITAR environment


Multiple users report access problems to resources in the O365 Dedicated/ITAR managed environment.


To resolve this issue, follow these steps.   


1. Create a detailed description of the issue 

You should include a specific description of the issue that users are reporting. This should include the following:

  • The kind of connections that are failing in the environment, such as Outlook, Outlook Web App (OWA), or Exchange Web Services (EWS).
  • Whether this issue is occurring intermittently or consistently
  • Detailed repro steps

2. Does the issue occur in a specific office or network segment or on a specific Exchange mailbox server?

If just a subset of users is affected, it's important to note (if known) what the common factor may be. It might be a specific office, network segment, or users on a specific Exchange mailbox server.

3. How long has this issue been occurring?

Provide the length of time this issue has been experienced or the date when it was first noticed.

4. Is there a WAN accelerator in the environment?

Provide the manufacturer and model of the WAN accelerator and info about how long it has been production. Provide any recent changes or updates.
For more information about WAN accelerators, see 2690045: Using WAN Optimization Controller or Traffic/Inspection devices with Office 365.

5. List of affected users.


It will be helpful to have at least five users who are experiencing this issue.


6. Diagnostic information:


The Customer On Demand Diagnostics (CODD) tool is a Windows client application that's used to address access issues that members of your organization might experience when they try to use Office 365 Dedicated services. 


This tool tests the following:   

  • Client system connectivity with the DNS server
  • Ability of a client system to access the Internet
  • Ability of the client to communicate with Exchange Online Dedicated client access servers

The output can be used to troubleshoot problems, including the following: 

  • Outlook Web App (OWA) main page fails to load
  • Unable to interact with the Client Access server that provides OWA access
  • Mail transport (SMTP-related) issues
  • Outlook client connectivity failures

To run the tool, follow these steps:

Download the tool from
  • Start the tool. Accept the end-user agreement and enter your vanity namespace (OWA URL). Then, select Click to troubleshoot.
    Screen shot of the Customer On Demand Diagnostics (CODD) tool page
  • The following output will be displayed. You can review the User's Guide ( for more information, including a matrix that provides details about when to escalate to MOSSUP.
    Screen shot of the output infomation
  • If the CODD tool can't be used, follow these steps: 

    Run Traceroute (tracert) by using the customer's vanity namespace (OWA URL). This follows a DNS round robin, and it queries the load balancer at the Exchange endpoint.

  • Perform an nslookup from the location of the problem for each of the endpoints. The network IP address will differ from the customer environment and from the managed environment.

    Nslookup -q=all
  • If the issue occurs in OWA, it will be helpful to have details from HttpWatch. The basic, free HttpWatch version can be downloaded from the following Symtec website:
  • IPConfig output for the local computer:

    ipconfig /all
  • Ping from client to destination:

  • Microsoft Internal Support Information

    Steps to reproduce.

    Product Bug Number: CI 10598, CI 16082, CI 38864,
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    Writer ID(email alias): v-six, v-maqiu
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    Article ID: 2451127 - Last Review: Dec 29, 2015 - Revision: 1