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    Resolved: Help Exchange Online Blocked

    Scheduled Pinned Locked Moved Firewalling
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    • J Offline
      jjones123
      last edited by

      Hello All.

      I recently setup pfsense as a SOHO firewall for my home office. Everything is working great except I can't get to my work email from home.

      Troubleshooting I did:

      • I attempted to connect without pfsense & that worked fine

      • I tried nslookup outlook.office365.com (from my PC & the router), both return appropriate results

      • I tried pinging outlook.office365.com (from my PC & the router), both time out

      • I ran the MS support tool that indicates my TCP traffic is being blocked on port 443 somewhere

      After running those I attempted to add an allow all rule to the Office365 published IPs but that did not work.

      I'm attaching the filter logs from the tests I ran, the firewall rules I configured, & the alias list of the exchange online IPs.

      As I'm a bit new to this / slightly confused I was hoping someone on the forum could give me some guidance.
      filterlog.png
      filterlog.png_thumb
      firewallrules.png
      firewallrules.png_thumb
      exchangeonline.png
      exchangeonline.png_thumb

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      • J Offline
        jjones123
        last edited by

        I performed some additional troubleshooting & I'm starting to think there is a configuration error somewhere else that is blocking this.

        I reset the router to factory default & disabled all firewall rules for testing. After it rebooted & access was restored I was still seeing the same behavior. As the network was wide open at that point I'm not really sure what the issue is.

        If anyone has any ideas I'd welcome them

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        • johnpozJ Offline
          johnpoz LAYER 8 Global Moderator
          last edited by

          Why are you using floating rules?  Why do you not just have the rules on your LAN interface?

          What are you lan rules?  Why would you not just use pfsense like it out of the box.. Then try and get fancy with your rules..

          An intelligent man is sometimes forced to be drunk to spend time with his fools
          If you get confused: Listen to the Music Play
          Please don't Chat/PM me for help, unless mod related
          SG-4860 25.07.1 | Lab VMs 2.8.1, 25.07.1

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          • J Offline
            jjones123
            last edited by

            I did try to use pfsense out of the box prior to configuring this. For some unknown reason out of the box it is not allowing access to exchange online (web of client).

            My LAN rules are the 3 stock lan rules (anti-lockout & the default allow any lan rules for IPv4 / v6).

            I can move the exchange access rule from floating over to the lan, but I don't believe that is the cause of the problem.

            On the WAN side there are only 3 rules as well (block private networks, block bogon networks, & a nat rule for plex)

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            • J Offline
              jjones123
              last edited by

              I ran a packet capture (see below) & I'm pretty sure this is not a firewall issue at this point. I'll open a new topic in the appropriate place to continue troubleshooting.

              When I try to access Exchange online or ping it I get the following in my packet capture:
              17:21:17.600215 [REDACTED] (oui Unknown) > Broadcast, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 40.97.153.82 tell [REDACTED], length 28
              17:21:19.601256 [REDACTED] (oui Unknown) > Broadcast, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 40.97.153.82 tell [REDACTED], length 28

              As I don't get any response to that & it just hangs I'm pretty sure its not a firewall issue

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              • johnpozJ Offline
                johnpoz LAYER 8 Global Moderator
                last edited by

                why would you be doing arp for exhange IP??  Is 40.97.153.82 suppose to be your gateway??

                An intelligent man is sometimes forced to be drunk to spend time with his fools
                If you get confused: Listen to the Music Play
                Please don't Chat/PM me for help, unless mod related
                SG-4860 25.07.1 | Lab VMs 2.8.1, 25.07.1

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                • J Offline
                  jjones123
                  last edited by

                  Apologies for the lack of clarity. 40.97.153.82 is one of the MS Exchange servers that I am attempting to reach. All I see in the logs is the ARP request going out & nothing coming back. I hope this helps

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                  • johnpozJ Offline
                    johnpoz LAYER 8 Global Moderator
                    last edited by

                    I get that that 40 address is the exchange server.. But unless your wan IP of pfsense thinks that network is local it would never ARP for the mac..  It would send traffic to its gateway, so while you should and get responses for ARP for your gateway IP.  You do not arp for IPs that are not local to your interfaces network.

                    What is the IP address of your pfsense wan?  There should be no reason why it would be on the same overlapping network as some public 40.97.153.82

                    An intelligent man is sometimes forced to be drunk to spend time with his fools
                    If you get confused: Listen to the Music Play
                    Please don't Chat/PM me for help, unless mod related
                    SG-4860 25.07.1 | Lab VMs 2.8.1, 25.07.1

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                    • J Offline
                      jjones123
                      last edited by

                      Thanks johnpoz. I have some troubleshooting to do when I get home

                      –-
                      Edit: posting resolution in this thread as well.

                      I got home & you were correct it was a configuration issue. Embarrassingly I setup my static IP  incorrectly on the WAN side. I've corrected the configuration & everything is working now. Kicking myself for looking at that 4 times & missing that the subnet was incorrectly configured.

                      Appreciate your help & patience

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