Re: apparent change in hostnames on LAN without admin intervention
On 12/14/2019 1:33 AM, Jape Person wrote:
> Hi folks. Did I miss something?
>
> I've had 3 Sid/testing systems running on the same LAN behind the same
> router for just shy of 3 years. Their static IP addresses have always
> been issued by the DHCP server on the router. Everything has been
> copacetic among the systems, with local and outside name resolution
> working with no issue.
>
> A little over a week ago the systems stopped being able to access each
> other by name. No changes were made in the settings or firmware of the
> router or of the local network settings on the systems.
>
> I discovered that all of the hostnames had changed from xxxxxx.local to
> xxxxxx. I've tried to determine the cause of this alteration in the
> hostnames on the LAN.
>
> Everything is working fine now that I've stopped trying to call the
> systems by the old xxxxxx.local names.
>
> Could this change be due to recent upgrades in software? (I upgrade
> every day.) I've reviewed the recent upgrades listed in
> /var/log/apt/history.log. I would have thought any deliberate change of
> this behavior would have been flagged by listchanges, but I can't find it.
>
> I'm just a home user / hobbyist, but this change occurring without any
> deliberate administrative action on my part makes the hairs stand up on
> my neck -- just a little bit.
>
> Advice or consolation would be welcomed.
>
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.
Note that the TLD '.lan' is sometime used.
1) https://www.xfinity.com/support/articles/list-of-approved-cable-modems
--
John Doe
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