do routers always need permanent DNS entries?

fli4l routers to internet need at least on permanent DNS-IP for *first*
DNS resolution. After first DNS resolution a exchange of DNS of the
specific provider is possible, okay. But if the first DNS resolution fails
then any DNS resolution fails. Do any other routers than fli4l
for internet connection need that, too? - I want to know whether it's
a characteristic of a router or of fli4l.

If "yes", then I see a big disadvantage using a router to
connect to internet. A simple standalone linux or win machine doesn't
need a permant DNS-IP. Using the function "peerdns" a standalone
PC usually gets working DNS *before* first DNS attempt. So a
direct internet connection never fails.

tia
Ekkard

Ekkard Gerlach <egerlach@aiai.de> wrote:
> fli4l routers to internet need at least on permanent DNS-IP for *first*
> DNS resolution.

What the hell is a fli4l router?

Are you talking about Dynamic DNS?

--
Cameron Kerr
cameron.kerr@paradise.net.nz : http://nzgeeks.org/cameron/
Empowered by Perl!

Cameron Kerr <cameron.kerr@paradise.net.nz> wrote in message news:<40ad9e3e@news.maxnet.co.nz>...
> Ekkard Gerlach <egerlach@aiai.de> wrote:
> > fli4l routers to internet need at least on permanent DNS-IP for *first*
> > DNS resolution.
>
> What the hell is a fli4l router?
>
> Are you talking about Dynamic DNS?

Google has been really flakey the past several days with my posts --
the one for this didn't make it through ;-(

To OP -- DNS is not needed/wanted on a router. Especially a router!
But this is really a GW on a floppy using DNS -- find something better
or do it by hand ;-)

The fli4l router is one of those router-on-a-floppy projects from days
past. This one is seems intent on making the process of configuring a
GW for a lan a "no-brainer". Unfortunately, it's specific to the
author's kind of setup and IMO it is a "no brains" approach. It must
be handy for some folks in Europe, though, as that seems where it's
most used.

http://www.fli4l.de/english/e_fli4l.htm

Unless OP has an old 486 laying around I would say ditch this thing.
It _may_ be useful for the clueless but any GW -- which is what this
thing really is -- that requires DNS is, shall we say, over
written/designed. In fact, even with an old 486 laying around, I
would ditch this thing. Seems to be based on 2.2.x kernels /;-)

hth,
prg
email above disabled

P Gentry <rdgentry1@cablelynx.com> wrote:

> To OP -- DNS is not needed/wanted on a router. Especially a router!

Just out of curiosity, why do you say that? (Especially ...)

--
Cameron Kerr
cameron.kerr@paradise.net.nz : http://nzgeeks.org/cameron/
Empowered by Perl!

Cameron Kerr wrote:
> P Gentry <rdgentry1@cablelynx.com> wrote:
>
>
>>To OP -- DNS is not needed/wanted on a router. Especially a router!
>
>
> Just out of curiosity, why do you say that? (Especially ...)

Sorry for butting in,

In a properly configured environment, the router will never have to
care about names, but make its routing decisions only on the IP in the
destination field. - Otherwise, imagine the overhead when for every
single packet the router will trigger a dns query...

One thing that should be emphasized is that in this "fli4l" thing,
the router acts as gateway and is - in most cases - one P of PPP.
In this situation, it may make sense to configure it as a dns proxy,
since only on this box the ppp option "usepeerdns" can take effect.

Normally, though, a plain router must rely on properly formed IP
packets that it will shove from A to B. So it is the clients' respon-
sibility to resolve names in the first place.


Cheers, Jack.

--
----------------------------------------------------------------------
My personal reading of the string "MicroSoft" expands to "NanoWeak"...

Cameron Kerr <cameron.kerr@paradise.net.nz> wrote in message news:<40ae6d8d@news.maxnet.co.nz>...
> P Gentry <rdgentry1@cablelynx.com> wrote:
>
> > To OP -- DNS is not needed/wanted on a router. Especially a router!
>
> Just out of curiosity, why do you say that? (Especially ...)

No need for Jack to be sorry about butting in ... we do that all the
time at my house ;-)

He sums it up pretty well. From my very quick/cursory look at fli4l,
I suspect its appeal is also related to the fact that EU ISPs
apparently use ISDN much more commonly -- so there is a call setup
that must be negotiated, but unlike POTS lines you can make _mutiple_
calls (two anyway with BRI) that would allow faxing while web surfing,
etc. On a GW fronting a lan a pre-canned setup solution is probably
attractive for the unknowing -- though it's not that difficult with
current distros.

Re: "especially"
The overhead is useless for just a MASQing router/GW/FW. The router
will be configured statically with a default route or have mutiple
network entries that associate a _network_ with an interface (for
forwarding). Dynamic routing uses its own protocols and it's all
based on IP addresses. Hosts need DNS -- not routers.

So far as a DNS proxy goes -- interesting but not really _that_
useful/advantageous for just a few home PCs (IMO;-). But here's a
nice "map" that gives a good idea of what it does. Of course, it's
also another item to setup and maintain -- just let the route cache on
the PCs do it ;-)
http://dproxy.sourceforge.net/

hth,
prg
email above disabled

Cameron Kerr <cameron.kerr@paradise.net.nz> wrote in message news:<40ae6d8d@news.maxnet.co.nz>...
> P Gentry <rdgentry1@cablelynx.com> wrote:
>
> > To OP -- DNS is not needed/wanted on a router. Especially a router!
>
> Just out of curiosity, why do you say that? (Especially ...)

Oops ... hit the send button too soon.

Running a DNS server for just a lan -- relying on ISP's name servers
for the internet -- usually "requires" a separate server on the lan
behind a FW. It can be tricky setting up the proper forwarding to the
ISP's servers (which may change witihout notice) if zone transfers
(for the private net) across a wan link are also involved.

I think many ISPs are discouraging zone transfers of their own zone
info to customers -- innocent contamination is bad enough, but DNS is
awfully leaky if not set up properly and the potential for
polluting/redirecting traffic can be a real pain to guard against.
LDAP directory services seem to be replacing the need for DNS in many
ways and can cut down on overhead wan traffic.

Certainly not the sort of problems you need to deal with on a border
router ;-)

regards,
prg
email above disabled