Change of IP - Update time

Steven Job lists at
Sun Jan 5 18:09:25 UTC 2003


It's all with the TTL.  DynDNS, ZoneEdit, DNS Made Easy,, they
all do their dynamic DNS with a low TTL.  Use 'dig' to see their results.

DNS Made Easy and Zone Edit for instance allows users to set their own TTLs.


On 5 Jan 2003, Peter Pfannenschmid wrote:

> Cheers!
> I have the following problem: I would like to use a name server (which
> is running fine and without problems) for some sort of dynamic DNS.
> Let's assume we have the host with IP address
> a.b.c.50; if I change this to a.b.c.51 and reconfigure the DNS server,
> there may be a delay up to two days until some client at the other end
> of the world gets the changed IP address when querying the host name.
> I suspect that the reason for this is the fact that multiple name
> servers can be involved in the resolution of a client's query, and
> every one of them could have the old IP address cached. So it will
> take some time until the new IP address is propagated. Please correct
> me if I am wrong here.
> On the other hand, there are services like which are
> specialized in this kind of stuff; these guys manage to propagate a
> changed IP address (a changed DNS record) throughout the world within
> five minutes after the changes have happened on their DNS servers. My
> question is: How do they achieve this?
> I am planning to experiment with the TTL and other parameters of my
> zone file. But before I do so, I would like to hear the opinions of
> the experts, since a too low TTL time may be considered as bad
> practice by the community.
> So what? Is there any method to achieve my goal, or should I set the
> TTL parameter to five minutes? If the latter is the case, is there a
> way for changing the TTL of the record for only one certain host of a
> domain (other than making a new zone)? I am using bind 9.1.3.
> Thank you very much,
> Peter

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