Andy --- thanks for all your help in diagnosing my situation and educating me!
This includes facts like the nature of these names (second_host was
indeed an example, did not know about the restriction on the names) and
use of dig.
I did some more experimentation on my system, and in fact my other
linux machine (which i'll just call 'secondhost', since 'second_host'
is illegitimate)
has no problems dropping the '.local', for ping and ssh.
And there is a difference between the two machines, which i didn't
think was important, but it must be. I.e., i think i've been
concealing evidence :(
My main machine ('firsthost') also connects to a little switch (via a
usb-to-ethernet
adapter) where two other machines are. These other machines are really
allergic to my router so cannot be plugged in directly to it. (I was amazed
at how easy it was to do this, the network manager on my main linux
machine had a little gui that offered to 'share the network' and it
all just worked.)
None of the names for any of the machines are served.
Now, just for reference, since you were so nice to answer all these questions:
My second linux machine is NXDOMAIN accourding to dig -t a, and that's
also the case for the two hypersensitive machines hiding behind my
main linux machine.
I haven't written anything in any /etc/hosts file anywhere, so the machines
all know each others ips in some other way.
If there's a way to determine if i'm running mDNS on my main linux
machine i'm certainly interested, but i don't want to be too greedy about this.
Because, after all, maybe it is reasonable that if my main linux
machine is sending all these packets around it needs more help
in determining what's on the local network.
If i get to the point where all my hardware is running free software
i may get greedier. :)
Thanks again for all your help!!
dan
On Sun, Apr 17, 2016 at 2:19 AM, Andy Smith <a...@strugglers.net> wrote:
> Hi Dan,
>
> On Sat, Apr 16, 2016 at 11:56:11PM -0700, Dan Hitt wrote:
>> On Sat, Apr 16, 2016 at 10:42 PM, Andy Smith <a...@strugglers.net> wrote:
>> > What doesn't work about it?
>>
>> It has no effect.
>>
>> So, if i do
>> ping second_host
>> i get "unknown host" from ping.
>
> OK. So all the hosts on your local network are getting .local as a
> domain name by suggestion of the DHCP server, but do you have a DNS
> server anywhere that is serving those names, or are you putting
> everything in /etc/hosts?
>
> I have done some tests on my own machines and I find that if I add
> "local." to my search line in /etc/resolv.conf it does seem to
> generate a DNS query for whatever.local. I do not have a DNS server
> that is serving the .local zone though, so it gives me NXDOMAIN. Of
> course if I would add google.com to my search list then a query for
> say, "mail" would turn into "mail.google.com" and I'd get an answer.
>
> So I wonder how your DNS is set up.
>
> If you are relying on the ISP-supplied router to serve DNS for names
> it is giving out by DHCP, well, some would and some wouldn't. You
> could check by running DNS diagnostic tools such as "dig" against
> the IP address of your router, e.g.:
>
> dig -t a second-host.local @192.168.0.1
>
> where "second-host.local" is what you want to look up, "192.168.0.1"
> is the IP address of your router and the "-t a" is asking for
> answers of type A: IPv4 address. If that gave an NXDOMAIN answer
> then there isn't any configuration mistake on your side, it's just
> that your router is not acting as a DNS server for that zone.
>
> (By the way, underscores are not permitted in Internet host names,
> so your "first_host" and "second_host" examples are not good, but I
> am guessing they were merely examples.)
>
>> Given this, is there any way to change the network's name?
>
> Although .local is reserved for mDNS, I think that unless you
> actually use mDNS you should be okay. As I say, I put ".local" in my
> search list and then saw DNS queries going out for those names so it
> probably doesn't interfere with (normal, unicast) DNS.
>
>> Is there any way to reload the dhclient.conf file without restarting
>> dhclient?
>
> These settings only take effect when you get a new lease or renew an
> existing one. So I think the answer is no. Is getting a new lease
> problematic? Normally on a DHCP network you don't tend to care if
> your IP address changes… (if you do care, you can get the DHCP
> server to give you the same one each time, but in your case that'd
> be a setting in the router which you don't manage).
>
>> This seems perplexing to me, because i'm not unhappy with any of the
>> ips i'm getting, i just want to be able to refer to hosts by shorter names.
>
> The issue is that these are different concepts and different
> services here, although they seem related and in your case are being
> provided by the same black box. The black box tells you your IP
> address and your host name and your domain name, so it seems logical
> that it should be able to also serve DNS for that zone, but it is
> not always the case.
>
> Cheers,
> Andy
>
> --
> http://bitfolk.com/ -- No-nonsense VPS hosting
