Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    SMTP Out being blocked

    Scheduled Pinned Locked Moved Firewalling
    13 Posts 2 Posters 1.1k Views 2 Watching
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • johnpozJ Offline
      johnpoz LAYER 8 Global Moderator @nabberuk
      last edited by johnpoz

      @nabberuk that log shows that it was allowed.. So not sure where you get the idea from that it was blocked.

      Why don't you just sniff on your wan - do you see the traffic go out.. 10 second test..

      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, 25.07.1

      N 1 Reply Last reply Reply Quote 0
      • johnpozJ Offline
        johnpoz LAYER 8 Global Moderator @nabberuk
        last edited by

        @nabberuk said in SMTP Out being blocked:

        I can't find much on TCP:SEC

        SYN and the EC just means ECE, CWR were also set..

        See
        https://www.rfc-editor.org/rfc/rfc3168#section-23.2

        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, 25.07.1

        1 Reply Last reply Reply Quote 0
        • N Offline
          nabberuk @johnpoz
          last edited by nabberuk

          @johnpoz

          Packet capture with a filter for port 465. This looks normal.

          16:05:09.928638 IP [external_IP].9908 > 64.233.184.109.465: tcp 0
          16:05:12.942825 IP [external_IP].9908 > 64.233.184.109.465: tcp 0
          16:05:18.953456 IP [external_IP].9908 > 64.233.184.109.465: tcp 0
          16:05:28.633324 IP [external_IP].56949 > 64.233.184.109.465: tcp 0
          16:05:31.639172 IP [external_IP].56949 > 64.233.184.109.465: tcp 0
          16:05:37.647045 IP [external_IP].56949 > 64.233.184.109.465: tcp 0

          johnpozJ 1 Reply Last reply Reply Quote 0
          • johnpozJ Offline
            johnpoz LAYER 8 Global Moderator @nabberuk
            last edited by

            @nabberuk yeah SEC is not anything odd.. Depend on what your application is setting.

            But you can clearly see traffic is leaving.. Just not getting any answers.. Which has nothing to do with pfsense.. Is your wan IP different? Maybe they don't want to talk to that IP, or maybe your isp is blocking.. But clearly from your sniff your sending that traffic out.. You getting an answer is out of pfsense control.

            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, 25.07.1

            N 1 Reply Last reply Reply Quote 1
            • N Offline
              nabberuk @johnpoz
              last edited by

              @johnpoz Thanks.

              I shall further investigate. I am using multiple WAN IP addresses but can't see any settings that would affect this.

              johnpozJ 1 Reply Last reply Reply Quote 0
              • johnpozJ Offline
                johnpoz LAYER 8 Global Moderator @nabberuk
                last edited by

                @nabberuk I did a simple nmap from pfsense to that IP... And I show it answering on the 465 port.

                Running: /usr/local/bin/nmap  -sS -P0 -e igb1 '64.233.184.109'
                Starting Nmap 7.91 ( https://nmap.org ) at 2022-02-21 10:14 CST
                Nmap scan report for wa-in-f109.1e100.net (64.233.184.109)
                Host is up (0.11s latency).
                Not shown: 996 filtered ports
                PORT    STATE SERVICE
                465/tcp open  smtps
                587/tcp open  submission
                993/tcp open  imaps
                995/tcp open  pop3s
                
                Nmap done: 1 IP address (1 host up) scanned in 10.48 seconds
                
                

                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, 25.07.1

                N 1 Reply Last reply Reply Quote 0
                • N Offline
                  nabberuk @johnpoz
                  last edited by nabberuk

                  @johnpoz It works fine from my home connection, just not in our colocation dc. I have raised a query with them to see if they are blocking anything.

                  Doing an nmap i get the following. Interestingly i can ping that IP from pfsense. Seems to be someone if blocking it upstream.

                  Host discovery disabled (-Pn). All addresses will be marked 'up' and scan times will be slower.
                  Starting Nmap 7.91 ( https://nmap.org ) at 2022-02-21 16:20 GMT
                  setup_target: failed to determine route to 64.233.184.109
                  WARNING: No targets were specified, so 0 hosts scanned.
                  Nmap done: 0 IP addresses (0 hosts up) scanned in 0.03 seconds
                  
                  johnpozJ 2 Replies Last reply Reply Quote 0
                  • johnpozJ Offline
                    johnpoz LAYER 8 Global Moderator @nabberuk
                    last edited by

                    @nabberuk said in SMTP Out being blocked:

                    just not in our colocation dc

                    Yeah quite possible they don't let that sort of traffic out? Or could be gmail is blocking your IP because it sends just spam ;)

                    But your clearly sending it - so something upstream is blocking it, or its getting there and your just not getting back an answer.. All of which has nothing to do with pfsense.

                    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, 25.07.1

                    1 Reply Last reply Reply Quote 1
                    • johnpozJ Offline
                      johnpoz LAYER 8 Global Moderator @nabberuk
                      last edited by

                      @nabberuk said in SMTP Out being blocked:

                      failed to determine route to 64.233.184.109

                      Where did you run that nmap?

                      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, 25.07.1

                      N 1 Reply Last reply Reply Quote 0
                      • N Offline
                        nabberuk @johnpoz
                        last edited by nabberuk

                        @johnpoz from pfsense (diag > command prompt) after installing the package.

                        Now ran it from the nmap option. think its defiantly being blocked upstream.

                        Running: /usr/local/bin/nmap  -sS -P0 -e igb0 '64.233.184.109'
                        Starting Nmap 7.91 ( https://nmap.org ) at 2022-02-21 16:31 GMT
                        Nmap scan report for wa-in-f109.1e100.net (64.233.184.109)
                        Host is up (0.0096s latency).
                        Not shown: 998 filtered ports
                        PORT    STATE SERVICE
                        993/tcp open  imaps
                        995/tcp open  pop3s
                        
                        Nmap done: 1 IP address (1 host up) scanned in 6.53 seconds
                        
                        johnpozJ 1 Reply Last reply Reply Quote 0
                        • johnpozJ Offline
                          johnpoz LAYER 8 Global Moderator @nabberuk
                          last edited by johnpoz

                          @nabberuk did you pick your interface? I would think pfsense should of been able to figure out which interface to send the traffic.. but maybe you have something odd setup with your routing.

                          Was that sniff you saw going out your wan - you sure that is the correct "wan" to be able to get there?

                          edit: so you can see other open ports (get answers) but not 465 - interesting..

                          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, 25.07.1

                          1 Reply Last reply Reply Quote 0
                          • First post
                            Last post
                          Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.