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  • DNS issue??

    Exchange 2003, new install. After much help, I was able to get this server up and running.. The first issue, no internal mail flowing, was resolved by a simple reboot of the Global Catalog server. I am at the point now, where I can send external mail, but I cannot recieve any external mail. I am fairly certain that I have DNS issues, but I somewhat at the mercy of my ISP. They have created a mail record on their end, but when I try to run the same NSLOOKUP on that record on my end, I can't get beyond MY DNS server.

    When running the MXTA, I get the following messages:

    POINTER record does not match SMTP instance
    The pointer (PTR) record localhost does not match any fully-qualified domain name of the SMTP instances on server AWEXCP01.

    Can anyone shed some light on this?

    Thanks in advance

  • #2
    Re: DNS issue??

    Your ISP should have created an MX record for your domain and an A host record for the public IP address of your exchange server.

    You MX record will be domain.com and your A host record should be something like mail which points to the public IP address of your exchange server. Your MX record then points to your A host record.

    You can check you MX recored by using nslookup and running the command set type=mx and then query the domain name

    Hope this helps

    Michael
    Michael Armstrong
    www.m80arm.co.uk
    MCITP: EA, MCTS, MCSE 2003, MCSA 2003: Messaging, CCA, VCP 3.5, 4, 5, VCAP5-DCD, VCAP5-DCA, ITIL, MCP, PGP Certified Technician

    ** Remember to give credit where credit is due and leave reputation points sigpic where appropriate **

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    • #3
      Re: DNS issue??

      Thanks Michael!

      They have created the MX record, but I can't succesfully run NSLOOKUP from the Exchange server (it's an internal IP). I have verified that our firewall is allowing port 25 traffice through. I am at the point now where, if sending mail to my Exchange test account with one of my Yahoo or Comcast accounts, it does not bounce back... but it never gets to my test machine. I THINK it's because my internal DNS does not have the information it needs ... ???

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      • #4
        Re: DNS issue??

        You say your firewall is allowing port 25 through but is it forwarded to the internal IP address of your exchange server. If you just open the port how is it supposed to find your Exchange box?

        You should be able to run nslookup from your exchange box as long as your DNS server has a reverse DNS zone configured and is also configured with root DNS servers (It should already be configured for this)

        Michael
        Michael Armstrong
        www.m80arm.co.uk
        MCITP: EA, MCTS, MCSE 2003, MCSA 2003: Messaging, CCA, VCP 3.5, 4, 5, VCAP5-DCD, VCAP5-DCA, ITIL, MCP, PGP Certified Technician

        ** Remember to give credit where credit is due and leave reputation points sigpic where appropriate **

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        • #5
          Re: DNS issue??

          Michael,

          OK.. I think you are pointing me down the correct path now.
          Our network guy is on vacation and he quickly made this change before leaving, and I think he may have hinked it up.
          Months ago, we build the same Exchange test system on a desktop machine, and SMTP was working (clue!). Someone decided to image the desktop machine for a needy user. I had to then go thru the rigamahroll of cleaning out all AD related stuff about that Exchange server install.

          Long story short... the entry in the firewall points to the OLD IP address (this would be that test machine).

          Here's where it might get tricky... I am somewhat comfortable (not 100%) about making this change on the firewall and editing in the correct internal IP number. However, being cautious..... would it be easier to change the IP number of my Exhange box back to what the desktop machine was???

          Thank you for the help!!!

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          • #6
            Re: DNS issue??

            Michael,


            Thanks so much for your help. Problem resolved. Apparently the firewall rule did not take when it was performed last week. I disabled the existing one, created a new one.. as soon as I saved it, messages started popping into Outlook. At least this exercise has familiarized me with lots of troubleshooting tips!!

            You rock!

            Thanks Again!!

            -Jeff

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            • #7
              Re: DNS issue??

              No problem mate,

              Glad you got it sorted.

              For future reference you should be able to telnet into your exchange SMTP server via the following command in dos:

              telnet domain.com 25

              You should get a responce back from the server which tells you that it's listening on that port and there is something there.

              Michael
              Michael Armstrong
              www.m80arm.co.uk
              MCITP: EA, MCTS, MCSE 2003, MCSA 2003: Messaging, CCA, VCP 3.5, 4, 5, VCAP5-DCD, VCAP5-DCA, ITIL, MCP, PGP Certified Technician

              ** Remember to give credit where credit is due and leave reputation points sigpic where appropriate **

              Comment


              • #8
                Re: DNS issue??

                Thanks again Michael,

                Now that I've got it working, I do want to circle back and figure this out.
                If I open a telnet session from my workstation and type in the IP of the exchange server, I can get connected.
                But, if I type in the name xXXXXX.XXx,
                Connecting To xxxxxxx.xxx...Could not open connection to the host, on port 25:
                Connect failed

                It seems my internal DNS is not aware of xxxxxxx.xxx ???

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                • #9
                  Re: DNS issue??

                  BTW. Nice Picture!

                  Comment


                  • #10
                    Re: DNS issue??

                    Originally posted by jmorrow84 View Post
                    Thanks again Michael,

                    Now that I've got it working, I do want to circle back and figure this out.
                    If I open a telnet session from my workstation and type in the IP of the exchange server, I can get connected.
                    But, if I type in the name xXXXXX.XXx,
                    Connecting To xxxxxxx.xxx...Could not open connection to the host, on port 25:
                    Connect failed

                    It seems my internal DNS is not aware of xxxxxxx.xxx ???
                    I've seen this issues before and sometimes it's your router / firewall not liking the connection going outside your network and then comming back in. Try it from your home PC or any other machine not on your network with internet access.

                    Yeah - It's my wife *Queue smarky comments from biggles*

                    Michael
                    Michael Armstrong
                    www.m80arm.co.uk
                    MCITP: EA, MCTS, MCSE 2003, MCSA 2003: Messaging, CCA, VCP 3.5, 4, 5, VCAP5-DCD, VCAP5-DCA, ITIL, MCP, PGP Certified Technician

                    ** Remember to give credit where credit is due and leave reputation points sigpic where appropriate **

                    Comment


                    • #11
                      Re: DNS issue??

                      Originally posted by jmorrow84 View Post
                      Thanks again Michael,

                      Now that I've got it working, I do want to circle back and figure this out.
                      If I open a telnet session from my workstation and type in the IP of the exchange server, I can get connected.
                      But, if I type in the name xXXXXX.XXx,
                      Connecting To xxxxxxx.xxx...Could not open connection to the host, on port 25:
                      Connect failed

                      It seems my internal DNS is not aware of xxxxxxx.xxx ???
                      Jmorrow84,

                      If you are pinging the internal name of your Exchange server from a workstation on the internal network, then YES, you do have a major DNS issue. My Exchange server is XMAIL, and I can ping it from workstations on the internal subnet. If my workstations are on another subnet, ie. via a WAN link in another domain, then I need to ping XMAIL.v.com.au (the local domain of the server is v.com.au).

                      If you can not ping the servers internal name either by Netbios or FQDN, then you have a job ahead of you. The lazy way out is to setup an A record in the DNS server with the server name and IP so that workstations can find it- but thats just sweeping the problem under the carpet.
                      Last edited by JDMils; 26th July 2007, 08:15.
                      |
                      +-- JDMils
                      |
                      +-- Regional Systems Engineer, DotNet programmer & Jack of all trades
                      |

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                      • #12
                        Re: DNS issue??

                        Originally posted by m80arm View Post

                        Yeah - It's my wife *Queue smarky comments from biggles*

                        Michael
                        Ah, the voice of hope over experience....
                        Tom Jones
                        MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
                        PhD, MSc, FIAP, MIITT
                        IT Trainer / Consultant
                        Ossian Ltd
                        Scotland

                        ** Remember to give credit where credit is due and leave reputation points where appropriate **

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                        • #13
                          Re: DNS issue??

                          Email has been dispatched to the real Mrs M80arm with URL to this thread. Now I am waiting for the sparks to fly. Muhahahahaha.

                          Jmorrow, ipconfig /flushdns on the machine you are running telnet from then try. Also remember to use the internal Domain Name when you telnet inside your firewall. Obviously the external DN when you telnet from outside the firewall.
                          Last edited by biggles77; 28th July 2007, 13:38.
                          1 1 was a racehorse.
                          2 2 was 1 2.
                          1 1 1 1 race 1 day,
                          2 2 1 1 2

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