[RRG] RE: [RAM] dns discover in map-and-encaps schemes

["Templin, Fred L" <Fred.L.Templin@boeing.com>]

> -----Original Message-----
> From: Dino Farinacci [mailto:dino@cisco.com] 
> Sent: Tuesday, March 20, 2007 3:29 AM
> To: Templin, Fred L
> Cc: rrg; ram@iab.org
> Subject: Re: [RAM] dns discover in map-and-encaps schemes
> 
> >> What happens when I type "ping <global-address>" on the source?
> >
> > Not quite certain what you mean; do you mean ping the source IP
> > address from the destination IP address after the source has done
> > the DNS mapping for the destination. The intent is the egress tunnel
> > router nearest the destination will have cached the source IP to
> > locator mapping and so the ping will succeed.
> 
> No, it was a simple statement about what if a host uses addresses to  
> send packets and not DNS names.
> 
> >> What if DNS is down, do I lose global connectivity?
> >
> > What happens if the DNS is down in today's Internet? You can
> 
> I can still "[ping,traceroute] <global-address>". I can still send  
> packets, I can still type in "http://192.168.0.1/"; in my browser.

Everything that works today for IPv4 would work tomorrow for IPvLX
for IPvLX nodes that are dual-stacked, which I anticipate would be
the normal case. The only nodes that would not be able to do a ping
to a global address  when the DNS is down would be IPv6-only nodes,
but IMHO those would only occur on very small devices on the very
extreme edges of the network.

> > ping any global IPv4 address and connect to any global IPv4
> > services by specifying an IP address instead of a FQDN, and
> > the very same will be true for this scheme. The only thing
> 
> How do you get locators when the DNS is down?

When the DNS is down, you will still be able to use IPv4 in the
same way we use IPv4 in the Internet today. The draft doesn't
explicity say this, but the preferred access method is IPv4,
with IPv6 used only for nodes that do not have a FQDN and IPv4
addresses in the global DNS. IPvLX augments the current
architecture, it does not compromise it.
 
> > you *won't* be able to do is ping IPv6 addresses and connect
> > to IPv6 services that are deeply embedded in distant sites,
> 
> A problem.

See above; the situation is no different than for the Internet
today. Again, IPvLX augments the existing architecture; it does
not compromise it.
 
> >> What if network administrators are totally against making 
> routers DNS
> >> servers?
> >
> > I want that the function be moved closer to the end devices, and
> > not in core routers - but, see more below:
> 
> That still won't make network administrators happier.

Howso? Why should the network administrator care if the end
node is simply behaving as an ordinary DNS resolver from an
outward appearance. That the end node is behaving as a
two-faced DNS server on behalf of its downstream-attached
devices (and internal virtual hosts) is no business of the
network administrator's.

Fred
fred.l.templin@boeing.com

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