Re: apparent change in hostnames on LAN without admin intervention
On Sat 14 Dec 2019 at 13:49:25 (-0500), Jape Person wrote:
> On 12/14/19 1:24 AM, john doe wrote:
> >
> > Assuming that you are using the router from your ISP, it is possible
> > that the firmware has been upgraded without your nolage.
> >
> > One way to prevent this could be (1), that is, use your own
> > router/server/gateway so you control everything on your LAN.
> >
> > I use an EMTA modem only from my ISP which is plugged into a perimiter
> > firewall.
> >
> > If you can't have an modem from your ISP, look at 'bridgemode'.
> >
> > If your not comfortable building your server from scratch, you can
> > simply buy a router that is accepted by your ISP .
> >
> > In other words, you need to choose one or the other if you go this way:
> > - Modem connected to router (most flexible of all)
> > - Combo modem/router in one box (les flexible but is more compact)
> >
> > If you use DHCP static lease, you should look at what the DHCP server is
> > providing as hostname and 'TLD', and also in the dhcp client (dhclient'
> > to see what you get from the DHCP server.
> >
> > The file '/etc/resolv.conf' should let you know what TLD is sent from
> > the DHCP server.
> >
> > Debian shouldn't modify your configuration files '/etc' without your nolage.
Depending on the packages chosen, /etc/resolv.conf is one file in /etc
that is modified by Debian. The resolvconf package lists 23 other
programs that it is designed to adjudicate between, for want of a
better term.
> > Note that the TLD '.lan' is sometime used.
That's another choice, like .local, that could always be issued as a
real TLD at some point in the future.
> > 1) https://www.xfinity.com/support/articles/list-of-approved-cable-modems
>
> I'm using my own router behind the modem provided by the ISP. I've
> never used a router provided by an ISP for controlling my network.
>
> I'm using a Luxul XWR-1750 which has been kept on the latest firmware
> available. Last upgrade was done early this year, long before the
> noted change in names.
>
> The router is set to provide static IP addresses and has the names of
> each of the systems associated with their MAC Addresses and IP
> Addresses.
Can you just clarify this? My router provides static IP addresses on
the basis of the MAC addresses, all the information being typed in¹
by me. It also lists the names of the other hosts, but only because
those hosts told it their names. IOW the router (cheap, $35) doesn't
issue hostnames, nor provide a DNS service itself. It also neither
knows nor cares what the domain name of the network is.
How much of this is the same on the router in your network?
¹ actually, of course, it deduces all but the last number in the
dotted quad.
Cheers,
David.
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