Re: Slashdot: Providers Ignoring DNS TTL?

[James <haesu () towardex com>]

On Fri, Apr 22, 2005 at 11:55:23PM -0400, Dean Anderson wrote:
> On Wed, 20 Apr 2005, Patrick W. Gilmore wrote:
>
> > On Apr 20, 2005, at 3:29 PM, Dean Anderson wrote:
> >
> > > > Or don't.  No one here cares if you do.  Reality trumps lab tests.
> > >
> > > "Reality" for the last ten years has been that no one did either PPLB
> > > or TCP DNS. That reality is changing. It'll probably start to change
> > > faster, sooner. Then, users will start to notice the problems.
> >
> > People have been using TCP applications on anycast for at least a  
> > decade, as I mentioned before.  Since DNS responses tend to be very  
> > short lived TCP session, it seems to me that if it works for other  
> > applications (e.g. HTTP), it should work for DNS.
>
> I don't know of any HTTP servers that do anycast.  But their failure to 
> take account of PPLB doesn't change anything. IF they are anycasting under 
> false assumptions, they'll have problems, too.

Remember that anycast configuration does not always require upper layer 
applications to specifically support "anycast featureset."  It can be done
in a setup similar to those currently being done with stateless/DNS, where
it is dependent of how you want to route your packets to anycast listener
address.

Just make sure your routing between anycasting nodes and requesting node
can actually deliver a clear picture, and it shouldn't be much of an issue
for the majority :)

-J



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James Jun
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