Hello Steffan,
you can usually run dnsdist and pdns on the same machine without
problems (actually this has been our default setup for years now).
dnsdist performs very well even with complex rulesets and a lot of
queries with almost no noticeable impact on performance.
Am 23.10.2023 um 10:05 schrieb Steffan Noord via Pdns-users:
Thanks.
I will read-in on dnsdist this week.
In the past i have treid it but dit something wrong in the config. I had
pdns and dnsdig on one server. I think it would be better to use a
sepperste vps for it.
Met vriendelijke groet,
Steffan Noord
Op ma 23 okt. 2023 10:00 schreef Andreas Danzer via Pdns-users
<pdns-users@mailman.powerdns.com <mailto:pdns-users@mailman.powerdns.com>>:
Hello Steffan,
that kind of attack is quite common these days. I would recommend
putting your authoriative nameservers behind dnsdist. Dnsdist acts as a
DNS firewall, proxy and loadbalancer.
We're running some rulesets on dnsdist, that e.g. dynamically block IPs
that "produce" unusual high numbers of NXDOMAIN answers with their
queries (which is usually the case with IPs taking part in PRSD
attacks). You can also limit the number of queries per IP or
loadbalance
queries to more than one backend DNS node. dnsdist is extreme powerfull
and versatile and the perfect tool to protect your DNS nodes.
To be able to see, which domains are actually attacked, you should not
use pdns query logging - it has a big performance impact which makes
the
situation even worse during an attack. Better use some traffic
capturing/sampling tools like pktvisor. It feeds data about the dns
queries to prometheus, which can be visualized with grafana. You can
use
that same setup (prometheus & grafana) to monitor your dndist and pdns
installations.
Am 20.10.2023 um 15:52 schrieb Steffan via Pdns-users:
> Well the problem was a small attack targeting a lot of subdomains
of a client.
>
> Oct 18 21:40:47 ns1 pdns_server[2135429]: Remote 117.54.16.252
wants 'payments.xxx.com <http://payments.xxx.com>|A', do = 1,
bufsize = 1232 (4096): packetcache MISS
> Oct 18 21:40:47 ns1 pdns_server[2135429]: Remote
2a02:2f0e:5fff:ffff::2 wants 'skyline.xxx.com
<http://skyline.xxx.com>|A', do = 1, bufsize = 1232 (4096):
packetcache MISS
> Oct 18 21:40:47 ns1 pdns_server[2135429]: Remote
2a04:c602:409:fe::27 wants 'app3.xxx.com <http://app3.xxx.com>|A',
do = 1, bufsize = 1232: packetcache MISS
>
> I comes from many different ips and only 3 minutes 150mb/s
>
> I forgot on that time that I had logging on. So it could be that
without the logging the dns would be fast enough to handle it
>
> Average bandwith load is abouth 160k/s so no big deal.
>
>
> Met vriendelijke groet,
>
> Steffan Noord
>
>
>
>
>
>
> -----Oorspronkelijk bericht-----
> Van: Victor Hugo dos Santos <listas....@gmail.com
<mailto:listas....@gmail.com>>
> Verzonden: vrijdag 20 oktober 2023 15:45
> Aan: All about using and deploying powerdns
<pdns-users@mailman.powerdns.com
<mailto:pdns-users@mailman.powerdns.com>>
> CC: steffanno...@gmail.com <mailto:steffanno...@gmail.com>
> Onderwerp: Re: [Pdns-users] multi dns server
>
> Hello there,
>
> The quantity of the domain, not necessarily reflect the quantity
of queries/load.
> you can have 5.000 domains with 1.000 QPS or you can have 1
domain with 15.000 QPS !! :-)
>
> Anyway, you should monitor your servers and see if this issue is
some kind of "normal" stuff or some kind of problem (attack, data
leak, misconfiguration, etc). When you detect the problem, then you
can decide what to do.
>
> About NS3, NS4, it is a totally valid option, not only to balance
the queries between servers, but to improve your HA too !!!
Nevertheless, you still need to detect where the problem is, if not,
you are only going to spend time with the new NS server but the
problem will still occur.
>
> Let us know what you find.
>
> Good luck
>
>
>
>
>
>
>
> On Fri, 20 Oct 2023 at 12:01, Steffan via Pdns-users
<pdns-users@mailman.powerdns.com
<mailto:pdns-users@mailman.powerdns.com>> wrote:
>>
>> Hello,
>>
>>
>>
>> 2 days ago my 2 dns servers has 150mbit of data to process and
the dns went down.
>> After the flood was stopped it came up again.
>>
>>
>>
>> Im using pdns 4.8.3 on centos with mysql backends
>>
>>
>> I just wondering what will the best idee to spread the risk
>>
>> It is handling about 5000 domains so not a very big system.
>>
>> is it better to use a ns3, ns4 to spread the loads on multi
servers Or
>> some kind of load balancing or multi ip setup on ns1 and ns2 on
multi
>> servers
>>
>>
>>
>> Any other idees are welcome
>>
>>
>>
>> With regard
>>
>>
>>
>> Steffan
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> Pdns-users mailing list
>> Pdns-users@mailman.powerdns.com
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>
>
>
> --
> --
> Victor Hugo dos Santos
> http://www.vhsantos.net <http://www.vhsantos.net>
> Linux Counter #224399
>
> _______________________________________________
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