If you've got more than one physical server, run a name server on two
different boxes. DNS requires very little CPU power, some memory (depending
on how many zones you're serving and whether the server is also used as a
caching server for the local network).
If you're running your whole presence on a single server then you're
probably right in that having redundant name servers doesn't buy you
anything. If the name server is down, the web server is down, the mail
server is down, the ftp server is down, etc. If any of those services,
however, are run on another machine then there are very real benefits to
having more than one name server. You can take a name server offline
without also shutting down your web or email functionality.
Best bet for someone who doesn't want to run two name servers is to have
someone else run your secondary server(s). That's what we do. There are a
few approaches to doing this. 1)some upstream providers will provide
secondary name services 2)there are commercial name services that will
provide primary and/or secondary DNS for a per-domain fee 3)work something
out with another small provider to provide secondary DNS for each other.
Jim
----- Original Message -----
From: "Eric Paynter" <[EMAIL PROTECTED]>
To: "Jim McAtee" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Friday, May 25, 2001 7:25 PM
Subject: Re: 2+ nameservers sharing 1 ip?
> I wonder how many people have two IPs pointing to the same box... I know
> some co-locates that give 25 IPs/rack space... This restriction in no way
> enforces redundancy. It really only makes things a hassle for companies
that
> have small business plans with only one IP.
>
> -Eric P.
>
> -------------------------------------------------------
> arctic bears - the internet - your way.
> email hosting from US$8/month, domains from US$19/year.
> http://www.arcticbears.com
>
>
> ----- Original Message -----
> From: "Jim McAtee" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Friday, May 25, 2001 6:03 PM
> Subject: Re: 2+ nameservers sharing 1 ip?
>
>
> > Yeah it arbitrarily tries to ensure that the DNS system has some degree
of
> > robustness. You're still free to screw it up, though.
> >
> > Wouldn't multiple name servers loadbalanced at the same IP address
> > effectively be a single server? Logically, it would seem so. You still
> > have no protection for network failures.
> >
> > I'll bet the reasoning behind the requirement also has something to do
> with
> > the way most DNS resolvers operate. If a query fails at one name
server,
> > the resolver tries another. Placing multiple name servers at the same
IP
> > address would defeat this behavior. It would be foolish (and
inefficient)
> > for a resolver to keep querying name servers at the same IP address in
the
> > hopes that a name server is going to magically start working at that
> > address.
> >
> > Why not run two ip addresses on the same box and have the name server
> answer
> > to either? Since you don't care about fault tolerance, this would be
one
> > solution.
> >
> > Jim
> >
> >
> > ----- Original Message -----
> > From: "tc lewis" <[EMAIL PROTECTED]>
> > To: "Lynn W. Taylor" <[EMAIL PROTECTED]>
> > Cc: <[EMAIL PROTECTED]>
> > Sent: Friday, May 25, 2001 6:20 PM
> > Subject: RE: 2+ nameservers sharing 1 ip?
> >
> >
> > >
> > > that reason is flawed. i think we all know that the whole "you should
> > > have 2 nameservers in different geographic locations for fail
purposes"
> > > ideal is often swept under the carpet.
> > >
> > > nsi shouldn't care about my fault tolerance; that's my concern.
> > >
> > > there are plenty of ways to network balance 1 ip.
> > >
> > > now we're back to there being 0 technical reasons. it's an arbitrary
> > > restriction network solutions has made and is ignorantly enforcing.
> > >
> > > -tcl.
> > >
> > >
> > > On Fri, 25 May 2001, Lynn W. Taylor wrote:
> > >
> > > > Sorry for the cross-post, but please post to one list only.
> > > >
> > > > The reason you have two name servers is so that you can turn one off
> and
> > > > still have one.
> > > >
> > > > Ideally, they'll be widely seperated so that there is no single
point
> of
> > > > failure that will shut both of them down.
> > > >
> > > > I don't know how to do that with just one IP.
> > > >
> > > > -----Original Message-----
> > > > From: tc lewis
> > > > Sent: Friday, May 25, 2001 4:25 PM
> > > > To: Jackie Fong
> > > > Cc: INTERNET@BCN {[EMAIL PROTECTED]}; INTERNET@BCN
> > > > {[EMAIL PROTECTED]}
> > > > Subject: RE: 2+ nameservers sharing 1 ip?
> > > >
> > > > how is it not legal?
> > > >
> > > > while irrelevant, one of the reasons is so all the domains i have
> using
> > > > nameserver x and nameserver y are effectively both using nameserver
x.
> > > > they already are -- i don't see the need to waste ip space and
various
> > > > other resources.
> > > >
> > > > -tcl.
> > > >
> > > >
> > > > On Fri, 25 May 2001, Jackie Fong wrote:
> > > >
> > > > > tcl,
> > > > >
> > > > > I don't think it's 'legal' to have two nameservers with the same
IP.
> > Why
> > > > > do you want to do that anyway? I don't see any reasons to do
> this...
> > > > >
> > > > > > the manage client interface (action=manage_nameserversmeservers)
> > doesn't
> > > > > > seem to allow me to create 2 nameservers with the same ip:
> > > > > >
> > > > > > Unable to create nameserver: Registry error, nameserver creation
> > failed
> > > > > > [Attribute value not unique]
> > > > > >
> > > > > > is there any technical reason for this? is this just an extra
> step
> > of
> > > > > > user error prevention? any way to get around it?
> > > > > >
> > > > > > -tcl.
> >
> >
>
>
