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MikeG1970's avatar
MikeG1970
Aspirant
Apr 20, 2025

RBK850 Not Connecting/Struggling to Connect to Microsoft Exchange Servers

Need some help figuring this one out - in the last week or so, my Outlook is often failing to connect (or trying to connect for upwards of 45 seconds) due to some blocking/connectivity issues. My PC ...
MikeG1970's avatar
MikeG1970
Aspirant
Apr 20, 2025

Thanks, but I already am using CloudFlare

 

Here is my IPv6 settings.

MikeG1970's avatar
MikeG1970
Aspirant
Apr 20, 2025

Here is my IPv4 setting.

  • CrimpOn's avatar
    CrimpOn
    Guru - Experienced User
    Apr 20, 2025

    Using a VPN is likely to result in using different DNS lookup.  Maybe change to Google (8.8.8.8)?

     

    If we knew the actual URLs that Office and One Drive use, the nslookup command might provide information.

     

    Does Windows (without the VPN) eventually connect and the problem is the extreme delay?

    • MikeG1970's avatar
      MikeG1970
      Aspirant
      Apr 20, 2025

      thanks for additional thinking here but I confirmed that the Cloudflare Warp does us their DNS (1.1.1.1).

       

      Oddly, this problem only started like 2 weeks ago.

       

      Yes, it ultimately it does connect, but it takes excessively long (could be as long as 30 to 45 seconds why it is "connecting to server").

       

      Again this happens in both Outlook when trying to first connect to Exchange and with OneDrive as I as try to save a file.

       

      At first I thought this was a MS Firewall issue, but the fact that it doesn't happen when I directly wired to the ONT (and only happens when I am directly wired to the Orbi) kind of confirms it is something with the Orbi.

      • MikeG1970's avatar
        MikeG1970
        Aspirant
        Apr 20, 2025

        Doing even more digging...it possibly appears to be related to an "old" bug that Netgear was alerted to previously!

         

        Seems to be related to IPv6 and "IPv6 Filtering" - Default setting is "secured" which research shows may cause issues (hence it was ticketed to support) ...I just switched it to "Open" and it appears to have resolved the issue.

         

        Some testing here - https://test-ipv6.com/

         

        1. With Cloudflare Warp (IPv6 Filtering set to Secure) - 10/10 (and quickly)
        2. With Cloudflare Warp off (and IPv6 Filtering set to Secure) - fails tests (and I get the delays with connecting with the Exchange servers)
        3. IPv6 Filtering set to Open (and Cloudflare Warp off) - test gets 10/10 quickly and I don't see any delays on connecting with the Exchange servers.

        I will clearly have to explore this more but this is promising so far!