Support

K-12 Forums

Talk with other K-12 network administrators in your state.

Or see all states.

Categories

Vanilla 1.1.4 is a product of Lussumo. More Information: Documentation, Community Support.

This discussion has been inactive for longer than 30 days, and is thus closed.

OpenDNS services: local DNS-MXentries

Bottom of Page

1 to 9 of 9

  1.  
    • CommentAuthorcykelsmeden
    • CommentTimeMay 21st 2009 edited
     permalink
    having my own mailserver and assp-proxy on my local network, I would like an option of "local MXentries"
    That is: when a MXrequest for @mymailserver.com, come from the local network, ODNS should reply with the local IP of the mailserver 192.168.1.8 rather than the public 80.127.126.80.
    - a bit in the same category as local URLS/shortcuts.
    or - are there another way to acomplish this? - except the obvious own DNSserver?

    finn
    • CommentAuthormarcusburge
    • CommentTimeMay 21st 2009 edited
     permalink
    Opendns has no method to answer custom local queries except for shortcuts, so your best bet for making lots of local queries would be an internal DNS server.

    edit: replaced internal "mail" server with internal "dns" server. sorry for the confusion, thanks for correcting me.
    • CommentAuthorRed Prince
    • CommentTimeMay 21st 2009
     permalink
    @cykelsmeden: Yes, the obvious: Your own DNS Server. Let it serve local IP addresses for your local network and forward all other requests to OpenDNS.

    @marcusburge: Don't you mean an internal DNS server?
  4.  permalink
    @red prince: you're right. I edited the post. sorry, i must have been thinking about something else when i was typing that.
    Thankful People: Red Prince
    • CommentAuthorcykelsmeden
    • CommentTimeMay 22nd 2009 edited
     permalink
    Ok, I've not expressed myself clearly.
    Yes, I was refering to "internal DNSserver". As OpenDNS is in fact a DNS server, and in general works as a normal DNS, except it is delivering modified IPs according to settings in my account. - hopefully we agree on that?
    Then I don't se why, if set on my account, a request on mxentry for not2old.dk, if asked from my IP, the answer would be substituted with 192.168.1.8 instead of the official 80.127.126.80 ??
    This would allow users(ie. firstclass) from within my local network to reach my assp server without having a local DNSserver to maintain and running.
    As now, if an internal user send mail to finn@not2old.dk he recieves a "domain not found" as the MX record points to the public IP, and the server resides on the private IP, and of course the ISP won't accept routing from inside via public IP to inside. - Hope I expressed myself better?

    finn
    • CommentAuthorrotblitz
    • CommentTimeMay 22nd 2009 edited
     permalink
    It is still not fully clear to me.
    Why do you use external public domain names for internal domains? This is bad practice, and any problems or conflicts are already predetermined then. Mail from internal users to internal users should not need to use an external domain or DNS service at all.

    "ODNS should reply with the local IP of the mailserver 192.168.1.8 rather than the public 80.127.126.80"
    "if asked from my IP, the answer would be substituted with 192.168.1.8 instead of the official 80.127.126.80"
    No, wrong expectation, OpenDNS cannot resolve internal domains or names, as it is an external public DNS service. However, you may try with adding your (double used) domain as VPN exception to see if OpenDNS at least return NXDOMAIN, and your equipment continues with internal resolution.

    You can solve your problem only with internal configuration, e.g. within ASSP or within your mail server. Not sure what mail server you are using, what e-mail clients are used, and where you get ASSP into the game, before or after your mail server. But you may need to review your design in general. It is likely that it doesn't work that way as is.

    "and of course the ISP won't accept routing from inside via public IP to inside."
    Why "of course"? For me this would work, but I wouldn't send internal mail over the external path for e.g. security reasons.
    • CommentAuthorRed Prince
    • CommentTimeMay 22nd 2009
     permalink
    As I said, use an internal DNS server to serve all requests for domains hosted on your internal network and forward everything else to OpenDNS. OpenDNS has no way of knowing that those domains are inside your network, but a local DNS server does (if you configure it properly).

    If you are saying that is your configuration and the requests are still going to OpenDNS, then your internal DNS server is not configured properly.
  8.  permalink
    No, I'm saying, you are absolutely right!
    But what I was trying to explain, was, that given how ODNS works, it should be able to answer mxrequests, coming from my internal network, which IP is configured in ODNS, when configured in my ODNSaccount, like "local maildomain mx:" mail.mydomain.dk = 192.168.1.8. Any other requests, not coming from my public IP would work just as normal, giving the public IP of my mailserver.
    If that was possible, it would spare my - and thousands private/sohonetworks - the need of configuring and maintain a local DNS.

    finn
    • CommentAuthorrotblitz
    • CommentTimeMay 26th 2009 edited
     permalink
    As @marcusburge said initially: "Opendns has no method to answer custom local queries". Only this counts. Addresses 192.168.0.0/255.255.0.0 are private and can never ever be resolved by any public DNS service.
    http://tools.ietf.org/html/rfc1918

    If you don't want to set up a DNS server, take the built-in one, the hosts file. It is supported on Unix/Linux, Windows and Mac.
    The related entry would look like:
    192.168.1.8 mail.mydomain.dk pop3.mydomain.dk smtp.mydomain.dk imap.mydomain.dk mydomain.dk
    depending on how your application programs (e.g. e-mail clients) "talk" to your mail server, i.e. by what names they call it.
    Is this what you wanted to know?

    Edit: Yes, the hosts file does not support MX entries, but see here:
    https://ssl.scroogle.org/cgi-bin/nbbwssl.cgi?Gw=hosts+file+mx+entries

1 to 9 of 9

  1.  

This discussion has been inactive for longer than 30 days, and is thus closed.