How I set up my domain on dynamic IP - TCP-IP

This is a discussion on How I set up my domain on dynamic IP - TCP-IP ; Is there anything wrong with this set up. I delegate to a DNS service that aliases to the dynamic IP service that provides my dynamic IP. Example.com (domain registration) ;; ANSWER SECTION: example.com. 86400 IN NS ns19.zoneedit.com. example.com. 86400 IN ...

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Thread: How I set up my domain on dynamic IP

  1. How I set up my domain on dynamic IP

    Is there anything wrong with this set up. I delegate to a DNS service that
    aliases to the dynamic IP service that provides my dynamic IP.

    Example.com (domain registration)
    ;; ANSWER SECTION:
    example.com. 86400 IN NS ns19.zoneedit.com.
    example.com. 86400 IN NS ns18.zoneedit.com.

    ZoneEdit.com (a free DNS service)
    ;; ANSWER SECTION:
    example.com. 7200 IN CNAME test.no-ip.com.
    example.com. 7200 IN NS ns19.zoneedit.com.
    example.com. 7200 IN NS ns18.zoneedit.com.
    example.com. 7200 IN SOA ns19.zoneedit.com. soacontact.zoneedit.com.
    1090610128 14400 7200 950400 7200

    ;; AUTHORITY SECTION:
    example.com. 7200 IN NS ns19.zoneedit.com.
    example.com. 7200 IN NS ns18.zoneedit.com.

    no-ip.com (a dynamic IP service)
    ANSWER SECTION:
    test.no-ip.com. 60 IN A 255.255.255.255 (my dynamic IP)





  2. Re: How I set up my domain on dynamic IP

    In article ,
    "strider" wrote:

    > Is there anything wrong with this set up. I delegate to a DNS service that
    > aliases to the dynamic IP service that provides my dynamic IP.
    >
    > Example.com (domain registration)
    > ;; ANSWER SECTION:
    > example.com. 86400 IN NS ns19.zoneedit.com.
    > example.com. 86400 IN NS ns18.zoneedit.com.
    >
    > ZoneEdit.com (a free DNS service)
    > ;; ANSWER SECTION:
    > example.com. 7200 IN CNAME test.no-ip.com.


    This CNAME record is invalid. A name cannot be both an alias and also
    have records of its own (such as the NS and SOA records below, which are
    required for delegated zones).

    You can use the CNAME record for www.example.com, but not for
    example.com itself.

    > example.com. 7200 IN NS ns19.zoneedit.com.
    > example.com. 7200 IN NS ns18.zoneedit.com.
    > example.com. 7200 IN SOA ns19.zoneedit.com. soacontact.zoneedit.com.
    > 1090610128 14400 7200 950400 7200
    >
    > ;; AUTHORITY SECTION:
    > example.com. 7200 IN NS ns19.zoneedit.com.
    > example.com. 7200 IN NS ns18.zoneedit.com.
    >
    > no-ip.com (a dynamic IP service)
    > ANSWER SECTION:
    > test.no-ip.com. 60 IN A 255.255.255.255 (my dynamic IP)


    --
    Barry Margolin, barmar@alum.mit.edu
    Arlington, MA
    *** PLEASE post questions in newsgroups, not directly to me ***

  3. Re: How I set up my domain on dynamic IP

    s> Is there anything wrong with this set up.

    Yes.

    s> example.com. 7200 IN CNAME test.no-ip.com.
    s> example.com. 7200 IN NS ns19.zoneedit.com.
    s> example.com. 7200 IN NS ns18.zoneedit.com.
    s> example.com. 7200 IN SOA ns19.zoneedit.com. soacontact.zoneedit.com.
    1090610128 14400 7200 950400 7200

    It's the classic attempt to erroneously make a domain name be both a
    client-side alias and a delegation point. A domain name cannot be both
    simultaneously.

  4. Re: How I set up my domain on dynamic IP


    "Jonathan de Boyne Pollard" wrote in message
    > It's the classic attempt to erroneously make a domain name be both a
    > client-side alias and a delegation point. A domain name cannot be both
    > simultaneously.


    How do I make example.com simply an alias pointing to example.dynamic.com
    and follow the rules.

    What I have done works as far as I can tell.

    Thanks



  5. Re: How I set up my domain on dynamic IP

    I'm thinking this is how I should handle a dynamic web site for
    example2.com. Place the alias in another domain that I own say example.com
    and for example2.com I can forward the whole domain.

    I do not forward for the example.com domain. So if no www is used these web
    requests get lost.

    These would make example2.com have a A record but no SOA records. Is that
    OK?

    Example2.com (domain registration)
    ;; ANSWER SECTION:
    example2.com. 86400 IN NS ns19.zoneDNS.com.
    example2.com. 86400 IN NS ns18.zoneDNS.com.

    ZoneDNS.com (a free DNS service)
    ;; ANSWER SECTION:
    example2.com.7200 IN CNAME test.no-ip.com.
    www.example.com.7200 IN CNAME test.no-ip.com.
    example.com. 7200 IN A 127.0.0.1.
    example.com. 7200 IN NS ns19.ZoneDNS.com.
    example.com. 7200 IN NS ns18.ZoneDNS.com.
    example.com. 7200 IN SOA ns19.ZoneDNS.com. soacontact.ZoneDNS.com.
    1090610128 14400 7200 950400 7200

    ;; AUTHORITY SECTION:
    example.com. 7200 IN NS ns19.ZoneDNS.com.
    example.com. 7200 IN NS ns18.ZoneDNS.com.

    no-ip.com (a dynamic IP service)
    ANSWER SECTION:
    test.no-ip.com. 60 IN A 255.255.255.255 (my dynamic IP)



  6. Re: How I set up my domain on dynamic IP

    In article ,
    "strider" wrote:

    > I'm thinking this is how I should handle a dynamic web site for
    > example2.com. Place the alias in another domain that I own say example.com
    > and for example2.com I can forward the whole domain.
    >
    > I do not forward for the example.com domain. So if no www is used these web
    > requests get lost.
    >
    > These would make example2.com have a A record but no SOA records. Is that
    > OK?


    No. If the domain is delegated, it *must* have NS and SOA records.

    >
    > Example2.com (domain registration)
    > ;; ANSWER SECTION:
    > example2.com. 86400 IN NS ns19.zoneDNS.com.
    > example2.com. 86400 IN NS ns18.zoneDNS.com.
    >
    > ZoneDNS.com (a free DNS service)
    > ;; ANSWER SECTION:
    > example2.com.7200 IN CNAME test.no-ip.com.


    This is a conflict. You showed NS records above, so it can't also have
    a CNAME record. It doesn't matter than the NS and CNAME records are on
    different servers (the parent server and the child server) -- the point
    is that either a name is an alias (in which case it gets all its records
    from the canonical name) or it has records of its own.

    > www.example.com.7200 IN CNAME test.no-ip.com.
    > example.com. 7200 IN A 127.0.0.1.
    > example.com. 7200 IN NS ns19.ZoneDNS.com.
    > example.com. 7200 IN NS ns18.ZoneDNS.com.
    > example.com. 7200 IN SOA ns19.ZoneDNS.com. soacontact.ZoneDNS.com.
    > 1090610128 14400 7200 950400 7200
    >
    > ;; AUTHORITY SECTION:
    > example.com. 7200 IN NS ns19.ZoneDNS.com.
    > example.com. 7200 IN NS ns18.ZoneDNS.com.
    >
    > no-ip.com (a dynamic IP service)
    > ANSWER SECTION:
    > test.no-ip.com. 60 IN A 255.255.255.255 (my dynamic IP)


    --
    Barry Margolin, barmar@alum.mit.edu
    Arlington, MA
    *** PLEASE post questions in newsgroups, not directly to me ***

  7. Re: How I set up my domain on dynamic IP

    In article <%YxOc.11387$pc.527347@news20.bellglobal.com>,
    "strider" wrote:

    > "Jonathan de Boyne Pollard" wrote in message
    > > It's the classic attempt to erroneously make a domain name be both a
    > > client-side alias and a delegation point. A domain name cannot be both
    > > simultaneously.

    >
    > How do I make example.com simply an alias pointing to example.dynamic.com
    > and follow the rules.


    The simplest method may be to find an HTTP redirector service. Have
    example.com resolve to their service's static address, and it can
    rewrite the URLs to example.dynamic.com.

    --
    Barry Margolin, barmar@alum.mit.edu
    Arlington, MA
    *** PLEASE post questions in newsgroups, not directly to me ***

  8. Re: How I set up my domain on dynamic IP


    > It's the classic attempt to erroneously make a domain name be both a
    > client-side alias and a delegation point. A domain name cannot be both
    > simultaneously.


    Thank you both for the comments. I would be pleased if you would further
    grace me with your thoughts.

    I have examined the RFC's further and have concluded that the use of the
    CNAME as I have done does not violate the DNS principles.

    Although RFC 2181: Clarifications to the DNS Specification states quite
    definitively that
    An alias name (label of a CNAME record) may . have no other data.
    I propose that this an over simplification of the specification as may be
    expected in a clarification.

    Going to RFC 1034: Domain names - Concepts and Facilities which is the
    source being clarified states
    If a CNAME RR is present at a node, no other data should be present; this
    ensures that the data for a canonical name and its aliases cannot be
    different.

    Rather than simply stating a rule this gives the justification for that
    rule.

    One must acknowledge that the situation where the Alias RRs provide SOA
    records and then refer via the CNAME to Canonical RRs with differing SOA
    records would be bad practice. The point made in RFC 1034 is to ensure that
    there will not be differing records.

    The Dynamic DNS service that I use ONLY contains the A record. Thus in order
    to provide a complete set of RRs it is necessary to provide SOA and NS
    records along with the CNAME which stands in place of the single A record
    located on the Dynamic DNS server. I have fulfilled the requirement not to
    provide other differing data.

    My use of the CNAME does not create both a client-side alias and a
    delegation point but rather it provides a single authoratative delegation
    point where the address record is redirected. Every request will be uniquely
    resolved. I think this falls within the specification.

    I will grant that were my DNS provider to allow Dynamic Update then I could
    reduce the workload on the resolver and the network however I see no
    violation of basic principles in what I have done.




  9. Re: How I set up my domain on dynamic IP

    In article ,
    "DragonFly" wrote:

    > > It's the classic attempt to erroneously make a domain name be both a
    > > client-side alias and a delegation point. A domain name cannot be both
    > > simultaneously.

    >
    > Thank you both for the comments. I would be pleased if you would further
    > grace me with your thoughts.
    >
    > I have examined the RFC's further and have concluded that the use of the
    > CNAME as I have done does not violate the DNS principles.
    >
    > Although RFC 2181: Clarifications to the DNS Specification states quite
    > definitively that
    > An alias name (label of a CNAME record) may . have no other data.
    > I propose that this an over simplification of the specification as may be
    > expected in a clarification.
    >
    > Going to RFC 1034: Domain names - Concepts and Facilities which is the
    > source being clarified states
    > If a CNAME RR is present at a node, no other data should be present; this
    > ensures that the data for a canonical name and its aliases cannot be
    > different.
    >
    > Rather than simply stating a rule this gives the justification for that
    > rule.


    It states the rule and then gives the reason for the rule. But even if
    you don't agree with the justification, you *still* have to obey the
    rule (just as you may be prosecuted for violating laws that you disagree
    with).

    >
    > One must acknowledge that the situation where the Alias RRs provide SOA
    > records and then refer via the CNAME to Canonical RRs with differing SOA
    > records would be bad practice. The point made in RFC 1034 is to ensure that
    > there will not be differing records.
    >
    > The Dynamic DNS service that I use ONLY contains the A record. Thus in order
    > to provide a complete set of RRs it is necessary to provide SOA and NS
    > records along with the CNAME which stands in place of the single A record
    > located on the Dynamic DNS server. I have fulfilled the requirement not to
    > provide other differing data.


    The problem is that CNAME records are *always* supposed to be followed.
    When a caching server processes your domain, it will cache both the NS
    records that came from the delegation and the CNAME record that comes
    from the authoritative server. This results in the inconsistency that
    the RFC refers to -- should it use those NS records or should it look
    for NS records at the target of the alias?

    > My use of the CNAME does not create both a client-side alias and a
    > delegation point but rather it provides a single authoratative delegation
    > point where the address record is redirected. Every request will be uniquely
    > resolved. I think this falls within the specification.


    The problem is that most caching DNS implementations are not designed to
    handle this case as you intend. The DNS specification says that they
    don't have to, so the programmers have not gone out of their way to do
    what you think is the right thing.

    --
    Barry Margolin, barmar@alum.mit.edu
    Arlington, MA
    *** PLEASE post questions in newsgroups, not directly to me ***

  10. Re: How I set up my domain on dynamic IP

    JdeBP> It's the classic attempt to erroneously make a domain name be
    JdeBP> both a client-side alias and a delegation point. A domain name
    JdeBP> cannot be both simultaneously.

    s> How do I make "example.com." simply an alias pointing to
    s> "example.dynamic.com." and follow the rules.

    Don't try to make it a delegation point as well. This means that the
    owners of the enclosing superdomain (i.e. "com.") will not be delegating
    it, of course.

    s> What I have done works as far as I can tell.

    Then your testing hasn't been anywhere near thorough enough.

  11. Re: How I set up my domain on dynamic IP

    s> Example2.com (domain registration)
    s> example2.com. 86400 IN NS ns19.zoneDNS.com.
    s> example2.com. 86400 IN NS ns18.zoneDNS.com.
    s>
    s> ZoneDNS.com (a free DNS service)
    s> example2.com.7200 IN CNAME test.no-ip.com.

    You are *still* making that classic error. A domain name cannot be both
    a delegation point and a client-side alias. Merely shuffling the
    resource records around a bit and changing the domain name does not get
    around that.

  12. Re: How I set up my domain on dynamic IP

    s> How do I make "example.com." simply an alias pointing to
    s> "example.dynamic.com." and follow the rules.

    BM> The simplest method may be to find an HTTP redirector service. [...]

    .... which, of course, presumes that "Internet" == "World Wide Web" and
    that the only service that he is providing to the world is HTTP.

    Not that that is the wrong approach, though. If the aliasing cannot be
    done through the DNS, then one is left with using whatever
    service-specific aliasing or redirection mechanisms there are. It's
    simply that one will have to deploy those mechanisms for *all* of the
    services that he provides.

  13. Re: How I set up my domain on dynamic IP

    s> How do I make "example.com." simply an alias pointing to
    s> "example.dynamic.com." and follow the rules.

    By the way: Stop using that chocolate-covered banana.




    How to achieve the *real* goal that you are trying to achieve is
    described in detail in articles in the "Support" section of "no-ip"'s
    web site. Read them.

  14. Re: How I set up my domain on dynamic IP

    > The problem is that CNAME records are *always* supposed to be followed.
    > When a caching server processes your domain, it will cache both the NS
    > records that came from the delegation and the CNAME record that comes
    > from the authoritative server. This results in the inconsistency that
    > the RFC refers to -- should it use those NS records or should it look
    > for NS records at the target of the alias?
    >


    There are no NS records at the target of the alias.

    > > My use of the CNAME does not create both a client-side alias and a
    > > delegation point but rather it provides a single authoratative

    delegation
    > > point where the address record is redirected. Every request will be

    uniquely
    > > resolved. I think this falls within the specification.

    >
    > The problem is that most caching DNS implementations are not designed to
    > handle this case as you intend. The DNS specification says that they
    > don't have to, so the programmers have not gone out of their way to do
    > what you think is the right thing.
    >

    You are right that I haven't considered caching. What would be cached.
    1) A copy of the authoritative zone RRs.- would work ok and still require a
    lookup of the address.
    2) A copy of the authoritative zone RRs.with the address resolved.- great
    but doubtful.
    3) Only the records at the target. ie only the A record and no SOA or NS -
    What could happen here.
    a) the cache could only answer address queries
    b) with no time to live the cached A record could live forever - my site
    would be unreachable via that cache
    c) with no time to live the cached A record could timeout immediately -
    would the cache retry or just drop the record? Retrys in an attempt to
    obtain a full zone set would be detrimental to traffic volume although
    minimal.
    d) other undefined behaviour - however if this is the "classic attempt" then
    the test suite should have some acceptable response from the cache. As a
    tester from time to time, my expectation is that this case would be handled,
    most likely by dropping the zone from the cache. Most dynamic sites should
    be of low volume and dropping this zone should free memory space in the
    cache rather than derail the speed ups provided by caching.






  15. Re: How I set up my domain on dynamic IP

    > Stop using that chocolate-covered banana.

    A valid comment at this point the discussion. My goal has changed from
    seeking a solution to seeking understanding of why. I think I'll take a
    break for some more reading before coming back with further questions.

    Thanks.




  16. Re: How I set up my domain on dynamic IP

    D> I have examined the RFC's further and have concluded that the
    D> use of the CNAME as I have done does not violate the DNS principles.

    Then your thinking is muddy.

    Why are you still pursuing this? We've told you that a domain name
    cannot be both a client-side alias and a delegation point. We've told
    you that what you are trying to do isn't the way to achieve your actual
    goal in the first place, and to stop using that chocolate-covered
    banana. And we've pointed you towards the articles on the web site of
    the service that you are using that tell you exactly how to achieve the
    actual goal that you are trying to achieve. (It's not exactly an
    uncommon thing to want to do, and your first stop really should have
    been the support service of the company whose services you are using,
    rather than Usenet.) Why are you trying to defend the classic error
    that you have made instead of reading the articles on "no-ip"'s web site?

    D> My use of the CNAME does not create both a client-side alias and
    D> a delegation point

    Yes it does. From your original message (your revised scheme is
    substantially identical, with merely the domain names changed):

    s> Example.com (domain registration)
    s> example.com. 86400 IN NS ns19.zoneedit.com.
    s> example.com. 86400 IN NS ns18.zoneedit.com.

    There's the domain name as a delegation point.

    s> ZoneEdit.com (a free DNS service)
    s> example.com. 7200 IN CNAME test.no-ip.com.

    And there's the domain name as a client-side alias.

    It's that simple.

    D> but rather it provides a single authoratative delegation point where
    D> the address record is redirected.

    Rubbish. That's not what it does at all. You've made the classic error
    of trying to make a domain name be both a client-side alias and a
    delegation point simultaneously. That doesn't work in theory; and it
    doesn't work in practice. (Hint: What do caching resolving proxy DNS
    servers do when, supposing that they have received those client-side
    alias and delegation data, they come to look up a resource record set
    for "example.com." that they have not looked up before? Further hint:
    The answer is not simple.)

  17. A domain name may not and cannot be both a client-side alias and a delegation point

    BM> This results in the inconsistency that the RFC refers to --
    BM> should it use those NS records or should it look for NS records
    BM> at the target of the alias?

    D> There are no NS records at the target of the alias.

    So, therefore, depending from what the answer is to Barry's question
    (which you haven't answered), in its search for delegation information
    it will end up with an "NS" resource record set comprising either two or
    zero resource records. Come on! Think!

    D> with no time to live the cached A record [...]
    ^^^^^^^^^^^^^^^
    Where did *this* fallacy come from ?

    D> if this is the "classic attempt" then the test suite should have
    D> some acceptable response from the cache.

    False. The standards say that one may not have a domain name be both a
    client-side alias and a delegation point. What makes you think that
    there should be a defined result in the case where one tries to do what
    it is stated one may not do ?

  18. Re: How I set up my domain on dynamic IP

    In article <4LZOc.35394$BU4.1626926@news20.bellglobal.com>,
    "DragonFly" wrote:

    > > The problem is that CNAME records are *always* supposed to be followed.
    > > When a caching server processes your domain, it will cache both the NS
    > > records that came from the delegation and the CNAME record that comes
    > > from the authoritative server. This results in the inconsistency that
    > > the RFC refers to -- should it use those NS records or should it look
    > > for NS records at the target of the alias?
    > >

    >
    > There are no NS records at the target of the alias.


    That's the problem. It's going to *expect* them to be there, because
    the alias supercedes any records at the source. You can't say "Follow
    the alias UNLESS you're looking for NS or SOA records."

    --
    Barry Margolin, barmar@alum.mit.edu
    Arlington, MA
    *** PLEASE post questions in newsgroups, not directly to me ***

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