knot-resolver-users May 2021

knot-resolver-users@lists.nic.cz

3 participants
4 discussions

Knot Resolver - redirect wildcard domain

by Milan Jeskynka Kazatel

Hello, could you please help me with knot resolver configuration in the case when I need to redirect each variation for the domain to some address. e.g. www.example.com, m.example.com, domain.example.com ... like wildcard record *.example.com 10.0.0.50 In my configuration is it handeled by file with static records -- load static records hints.add_hosts('/etc/knot-resolver/static_records.txt') which contains address to be redirected and the domain. 10.0.0.50 1xbet.com 10.0.0.50 thelotter.com 10.0.0.50 webmoneycasino.com 10.0.0.50 betworld.com 10.0.0.50 bosscasino.eu 10.0.0.50 sportingbull.com But I´m not able to handle the correct syntax for a wildcard domain redirection. Best regards, -- Smil Milan Jeskyňka Kazatel

2 years, 8 months

Knot Resolver 5.3.2

by Tomas Krizek

Dear Knot Resolver users, Knot Resolver 5.3.2 has been released! Security -------- - validator: fix 5.3.1 regression on over-limit NSEC3 edge case (!1169) Assertion might be triggered by query/answer, potentially DoS. Improvements ------------ - cache: improve handling write errors from LMDB (!1159) - doh2: improve handling of stream errors (!1164) Bugfixes -------- - dnstap module: fix repeated configuration (!1168) - validator: fix SERVFAIL for some rare dynamic proofs (!1166) - fix SIGBUS on uncommon ARM machines (unaligned access; !1167, #426) - cache: better resilience on abnormal termination/restarts (!1172) - doh2: fix memleak on stream write failures (!1161) Full changelog: https://gitlab.nic.cz/knot/knot-resolver/raw/v5.3.2/NEWS Sources: https://secure.nic.cz/files/knot-resolver/knot-resolver-5.3.2.tar.xz GPG signature: https://secure.nic.cz/files/knot-resolver/knot-resolver-5.3.2.tar.xz.asc Documentation: https://knot-resolver.readthedocs.io/en/v5.3.2/ -- Tomas Krizek PGP: 4A8B A48C 2AED 933B D495 C509 A1FB A5F7 EF8C 4869

4 years, 10 months

Disable qname minimization

by Bjoern Franke

Hi, I recently stumbled about the following issue with postfix: DANE TLSA lookup problem: Host or domain name not found. Name service error for name=_25._tcp.smtp-relay-in-s1.neusta.de type=TLSA: Host not found, try again Postfix uses knot-resolver and I found [1] as a possible similar issue with unbound. I would like to test if the issue persists with disabled qname minimization, but it seems to be no configurale option. Kind Regards Bjoern [1] http://postfix.1071664.n5.nabble.com/Mail-deferred-TLSA-lookup-error-td1074…

4 years, 10 months

Writing a module to forward a query to another nameserver if recursive resolution fails

by Paul Furtado

Hello, We operate recursive resolvers in our network in AWS and from within the AWS network there are certain authoritative nameservers that block large swaths of the AWS IP range, causing resolution to fail for us. So I'm attempting to write a module that will handle failures reaching external resolvers and retry the query by forwarding it to a major resolver like cloudflare DNS. We push a ton of DNS query traffic so we do not want to simply forward to a public resolver, we only want to forward if recursion doesn't work for some reason. I've poured through the documentation and source code and tried to hook a variety of places, but I can't seem to find a good spot to hook the request failure. The finish layer allows me to hook the SERVFAIL, but by then it is too late to do anything. Using a simple policy, I was actually able to do something close by calling ensure_answer(), clearing the answer, setting the same forwarding flags as the forward policy, and then calling ensure_answer() again and I could see the query getting sent to cloudflare, so it seems like this is possible, but at the policy level it's too early to know if a query will result in a SERVFAIL. Could anyone point me in the right direction here? Thank you! Paul

4 years, 10 months

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knot-resolver-users May 2021