Re: stretch and DNS name resolution service for other devices on a LAN

[David Wright <deblis@lionunicorn.co.uk>]

On Tue 23 Jan 2018 at 16:06:01 (-0000), Andy Hawkins wrote:
> Hi,
> 
> In article <[🔎] 20180123144327.GA6815@alum>,
>            David Wright<deblis@lionunicorn.co.uk> wrote:
> > This would all be a step in the wrong direction here. Point (2) was
> > that using IPv6 over CAT5 avoids swamping the router. (Of course,
> > that's already been snipped out of the thread.) If the DHCP server
> > is down, then the router is down, and there are no links to anywhere
> > except the CAT5 cable I've just connected.
> >
> > So why would I worry about whether the IPv4 had reconfigured itself
> > when I've got a perfectly good dedicated IPv6 link between the two
> > computers? And why should I be worrying about DHCP failures?—the
> > only time my router is dead is during power cuts.
> 
> You were giving your reasoning for using IPv6 as being able to handle direct
> cable connections between devices.
> 
> I was simply explaining that you don't need IPv6 to do this, as IPv4 will
> probably fall back to 'link local' addresses if they receive no response
> from a DHCP server (which they won't, as all they're connected to is some
> other PC). 

You still don't quite understand what I'm doing, so here's a diagram
(needs monospace font):

[My Laptop] --- wireless connection IPv4 --- [Router] --- Internet Modem
     |                                         / |
     | CAT5 cable IPv6                        /  |
     |                                       /   | wireless/wired
[My Desktop] --- wireless connection IPv4 __/    | connections
                                                 | IPv4
                                                 |
                                                [TVs]

> Both devices will allocate themselves an address in the 'link local' range,
> and these addresses can then be used for communicating between the devices.

… but meanwhile *I* can carry on using them both on the Internet
while transfers are taking place, and the TVs are unaffected by
any excessive traffic through the router.

In the case where a desktop is wired to the router, then just that
PC would lose its connectivity to all other machines (except
[My Laptop] of course) during a CAT5 connection (assuming it had
just the usual single ethernet port).

Cheers,
David.