Questions

Exchange Server 2003 & DNS Problems

Tags:
+
0 Votes
Locked

Exchange Server 2003 & DNS Problems

jizunkmizail
I'm having some problems setting up an Exchange server, and I think it's because I have my DNS server set up incorrectly. I have an A record set up for mydomain.com, and then a CNAME record set up for mail.mydomain.com. When I do an nslookup on mail.mydomain.com, I get the correct (local) IP of 192.168.0.1, however when I try to ping mail.mydomain.com, it doesn't work because it's trying to ping the global IP of the server. This doesn't make a lot of sense to me. Any ideas?

From a client computer, all of the emails I try to send to another local user get bounced back with this error:

#5.1.8 smtp;553 5.1.8 <recipient@mydomain.com>... Domain of sender address sender@servername.local does not exist>

Thanks in advance,
Scott
  • +
    0 Votes
    CG IT

    whats the MX record say?

    +
    0 Votes
    jizunkmizail

    the MX record for mydomain.com points to mail.mydomain.com

    but, like I said, for some reason mail.mydomain.com seems to be getting resolved to the global IP instead of the local one. when i use nslookup, it resolves correctly, but if i use ping, it tries to ping the global ip.

    this may or may not be the problem, but it's the only thing i can think of at the moment.

    thanks for the reply,
    scott

    +
    0 Votes

    DNS

    CG IT

    It's pretty simple. your public domain name that is your FQDN must resolve to your public address for anyone on the internet to find you.

    for you LAN, for users to find all services on the LAN, queries must resolve to LAN addresses.

    Since your private Domain Name is <domain name>.local all DNS records on the DNS server in the forward lookup zone for the Zone <domain name>.local need to have the[ .local = local server address ]records.

    What sounds like what is happening is that you have a MX record in DNS that says MX = <domain name.com/org/net/ > ..... therefore mail destined for the LAN doesn't get delivered because LAN domain is .local not .com

    So, to resolve this, for your public name to get to you, you need an authoritative DNS server listed at your domain registrar that says <domain name>.com/org/net is <public IP address> or an *.<domain name>.com/org/net [asterisk is wildcard].

    your internal DNS server is as I mentioned above needs internal records including the MX record that is resolved to .local

    +
    0 Votes
    mike.walker

    MAILFLOW: Based on the NDR message "sender@servername.local does not exist", you have your internal domain called domain.local. Exchange uses the domain name as the primary SMTP address by default (which is used as FROM:), so you have to modify the recipient policy to be @domain.com instead.

    DNS: Unless you are a large company hosting your own DNS records for the Internet, you should not have anything about mail.domain.com or MX records in your internal DNS. Your MX record needs to be hosted externally so people on the Internet know the public IP address where to send mail for your domain. The device receiving traffic on that IP address (router, firewall, etc.) needs to redirect port 25 traffic to the Exchange server. You will have a host(A) record for the name of the server which handles the mail so internal clients can resolve the server. The ping may be getting blocked by a firewall, so may not be a good test of connectivity. try "TELNET servername 25" to see if you get the SMTP banner from Exchange.

    http://technet.microsoft.com/en-us/library/aa996996.aspx

    http://www.amset.info/exchange/dnsconfig.asp

    http://www.computerperformance.co.uk/exchange2003/exchange2003_MX_records.htm

  • +
    0 Votes
    CG IT

    whats the MX record say?

    +
    0 Votes
    jizunkmizail

    the MX record for mydomain.com points to mail.mydomain.com

    but, like I said, for some reason mail.mydomain.com seems to be getting resolved to the global IP instead of the local one. when i use nslookup, it resolves correctly, but if i use ping, it tries to ping the global ip.

    this may or may not be the problem, but it's the only thing i can think of at the moment.

    thanks for the reply,
    scott

    +
    0 Votes

    DNS

    CG IT

    It's pretty simple. your public domain name that is your FQDN must resolve to your public address for anyone on the internet to find you.

    for you LAN, for users to find all services on the LAN, queries must resolve to LAN addresses.

    Since your private Domain Name is <domain name>.local all DNS records on the DNS server in the forward lookup zone for the Zone <domain name>.local need to have the[ .local = local server address ]records.

    What sounds like what is happening is that you have a MX record in DNS that says MX = <domain name.com/org/net/ > ..... therefore mail destined for the LAN doesn't get delivered because LAN domain is .local not .com

    So, to resolve this, for your public name to get to you, you need an authoritative DNS server listed at your domain registrar that says <domain name>.com/org/net is <public IP address> or an *.<domain name>.com/org/net [asterisk is wildcard].

    your internal DNS server is as I mentioned above needs internal records including the MX record that is resolved to .local

    +
    0 Votes
    mike.walker

    MAILFLOW: Based on the NDR message "sender@servername.local does not exist", you have your internal domain called domain.local. Exchange uses the domain name as the primary SMTP address by default (which is used as FROM:), so you have to modify the recipient policy to be @domain.com instead.

    DNS: Unless you are a large company hosting your own DNS records for the Internet, you should not have anything about mail.domain.com or MX records in your internal DNS. Your MX record needs to be hosted externally so people on the Internet know the public IP address where to send mail for your domain. The device receiving traffic on that IP address (router, firewall, etc.) needs to redirect port 25 traffic to the Exchange server. You will have a host(A) record for the name of the server which handles the mail so internal clients can resolve the server. The ping may be getting blocked by a firewall, so may not be a good test of connectivity. try "TELNET servername 25" to see if you get the SMTP banner from Exchange.

    http://technet.microsoft.com/en-us/library/aa996996.aspx

    http://www.amset.info/exchange/dnsconfig.asp

    http://www.computerperformance.co.uk/exchange2003/exchange2003_MX_records.htm