Mailinglist Archive: opensuse (1108 mails)

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Re: [opensuse] kernel versions
On 2018-08-19 9:36 a.m., Carlos E. R. wrote:
On 2018-08-19 14:28, Anton Aylward wrote:
On 2018-08-18 9:03 p.m., don fisher wrote:
and the dns-resolver wasn't polluting the world with silly resolve.conf
error
messages. One would be fine, but hundreds serve no purpose as far as I know.

That too depends on
- the DNS resolver you use.

Nonono.

He refers to a message on the log saying that the file has been altered
and not doing something with it.

Yes, there are a HUGE number of possible messages a DNS server COULD send!
Lame server, network problems,

I also mentioned the ISP/DHCP connection.
Most ISPs that use DHCP use the protocol to include a set of DNS addresses, and
unless you take extraordinary configuration measures to strap down your
/etc/resolv.conf by one means or another, every time the DHCP reconnects it
reloads that.

I can't recall what the measures are, but mine is to have a model/switch that
talks to the USP and my PC is plugged into that switch and uses DNSMasq and has
a local address. This was a result of advice I was given here.

On bad days, maintenance days, stormy days and very, very wet days and the like,
my cable service become ... difficult and I can expect poor signals and dropped
connections and restarts. I'm sure that the cable modem is given a hole new
set of the same old same old DNS values on the DHCP exchange every time, but so
what? I have messaging for that turned off at the cable modem. I'm sure its
there in the cable modem's log, but that never bothers my system. The DNS
values I use are configured in the /etc/dnsmasq.conf file.

But wait! Using DNSMasq is the way the basic system gets installed, is it?
You have to actually go to deliberate lengths to configure it and make the
system use it, and you need to research a good set of reliable public DNS server
to put in the config file.


I'm sure there are other ways to achieve this end.
I'm sure that you can configure the /etc/rsyslog.conf to do flood-limiting for
the DNS messages.
rate limiting started with rsyslog 5.7.1 back in what, 2010.
There's been a lot written on it of you google.
You need to install or activate rsyslog's 'imjournal' module then add to the
config file something like:

$ModLoad imjournal
$imjournalRatelimitInterval 600
$imjournalRatelimitBurst 20000

And of course it is a lot easier with systemd-journald.
By default it allows 1,000 messages within a 30 second period.
The limits are controlled in the /etc/systemd/journald.conf file.
For example, that default is written as:
RateLimitInterval=30s
RateLimitBurst=1000
but you can change that.
See journald.conf(5) for details.


So: the message I want to get across is
a) Linux is configurable but you need to make the effort
b) Methods, man pages, examples are all out there.
But you need to make the effort to google for them and read them


--
A: Yes.
> Q: Are you sure?
>> A: Because it reverses the logical flow of conversation.
>>> Q: Why is top posting frowned upon?


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