[Pdns-users] Slow query and SERVERFAIL from local pdns_recursor

Thomas Mieslinger miesi at mail.com
Wed Sep 9 08:05:40 UTC 2020


Hi Christian,

Hetzner might filter ip fragments. Please try if your situation gets
better if you set udp-truncation-threshold to a reasonable low value.

By default pdns-recursor does dnssec. I would like to suggest to set
+dnssec on your dig queries.

A possible workaround for the vmware.com problems is to add a negative
trust anchor for vmware.com. in pdns config.

Cheers Thomas

On 9/8/20 2:16 PM, Christian Degenkolb via Pdns-users wrote:
> Hi,
>
> I set the trace=yes option in the recursor config an redid the tests for
> pubs.vmware.com.
>
> The log can be found here https://paste.debian.net/hidden/07526601/
>
> I found two timeouts in the logs
>
> Line 41:
> Sep  8 10:21:54 rho pdns_recursor[25208]: [3] pubs.vmware.com: Resolved
> 'vmware.com' NS ns01.vmwdns.com to: 45.54.11.1
> Sep  8 10:21:54 rho pdns_recursor[25208]: [3] pubs.vmware.com: Trying IP
> 45.54.11.1:53, asking 'pubs.vmware.com|A'
> Sep  8 10:21:56 rho pdns_recursor[25208]: [3] pubs.vmware.com: timeout
> resolving after 1501.63msec
> Sep  8 10:21:56 rho pdns_recursor[25208]: [3] pubs.vmware.com: Trying to
> resolve NS 'ns04.vmwdns.com' (2/8)
>
> But a request to the 45.54.11.1 for pubs.vmware.com come back within 11
> msec.
>
> $ dig -t A @45.54.11.1 pubs.vmware.com
>
> ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> -t A @45.54.11.1
> pubs.vmware.com
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 24122
> ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
> ;; WARNING: recursion requested but not available
>
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 4096
> ;; QUESTION SECTION:
> ;pubs.vmware.com.INA
>
> ;; ANSWER SECTION:
> pubs.vmware.com.30INCNAME   pubs.vmware.com.ds.edgekey.net.
>
> ;; Query time: 11 msec
> ;; SERVER: 45.54.11.1#53(45.54.11.1)
> ;; WHEN: Tue Sep 08 13:29:57 CEST 2020
> ;; MSG SIZE  rcvd: 88
>
> and a seconds timeout in line 159:
>
> Sep  8 10:21:56 rho pdns_recursor[25208]: [3] e751.dscx.akamaiedge.net:
> Trying IP 2.16.106.23:53, asking 'e751.dscx.akamaiedge.net|A'
> Sep  8 10:21:57 rho pdns_recursor[25208]: [3] e751.dscx.akamaiedge.net:
> timeout resolving after 1501.74msec
> Sep  8 10:21:57 rho pdns_recursor[25208]: [3] e751.dscx.akamaiedge.net:
> Trying to resolve NS 'n3dscx.akamaiedge.net' (2/8)
>
> Same picture here with a very good response time.
>
> $ dig -t A @2.16.106.23 e751.dscx.akamaiedge.net
>
> ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> -t A @2.16.106.23
> e751.dscx.akamaiedge.net
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7947
> ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
> ;; WARNING: recursion requested but not available
>
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 4096
> ;; QUESTION SECTION:
> ;e751.dscx.akamaiedge.net.INA
>
> ;; ANSWER SECTION:
> e751.dscx.akamaiedge.net. 20INA104.111.214.47
>
> ;; Query time: 5 msec
> ;; SERVER: 2.16.106.23#53(2.16.106.23)
> ;; WHEN: Tue Sep 08 13:31:32 CEST 2020
> ;; MSG SIZE  rcvd: 69
>
>
> To check that this is not a vmware.com problem I tested some more and
> got the same timeouts.
>
>
> One more example for
>
> $dig nameservers.dnscheck.co @127.0.0.1
>
> ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> nameservers.dnscheck.co
> @127.0.0.1
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 23852
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
>
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 4096
> ;; QUESTION SECTION:
> ;nameservers.dnscheck.co.INA
>
> ;; Query time: 3005 msec
> ;; SERVER: 127.0.0.1#53(127.0.0.1)
> ;; WHEN: Tue Sep 08 12:15:29 CEST 2020
> ;; MSG SIZE  rcvd: 52
>
> can be found here https://paste.debian.net/hidden/b48a78a2/.
>
> This time multiple timeout regarding the root name servers, for example
> g.root-servers.net
>
> Sep  8 12:15:21 rho pdns_recursor[25208]: [50] nameservers.dnscheck.co:
> Resolved '.' NS g.root-servers.net to: 192.112.36.4
> Sep  8 12:15:21 rho pdns_recursor[25208]: [50] nameservers.dnscheck.co:
> Trying IP 192.112.36.4:53, asking 'nameservers.dnscheck.co|A'
> Sep  8 12:15:22 rho pdns_recursor[25208]: [50] nameservers.dnscheck.co:
> timeout resolving after 1501.63msec
> Sep  8 12:15:22 rho pdns_recursor[25208]: [50] nameservers.dnscheck.co:
> Trying to resolve NS 'j.root-servers.net' (2/13)
>
> Where a direct request via dig works like a charm.
>
> $ dig -t A @192.112.36.4 nameservers.dnscheck.co
>
> ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> -t A @192.112.36.4
> nameservers.dnscheck.co
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18641
> ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 6, ADDITIONAL: 13
> ;; WARNING: recursion requested but not available
>
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 4096
> ; COOKIE: ce9eaf15bb34977b41354b5f5f576c3841785bfba5901e93 (good)
> ;; QUESTION SECTION:
> ;nameservers.dnscheck.co.INA
>
> ;; AUTHORITY SECTION:
> co.172800  INNSns5.cctld.co.
> co.172800  INNSns1.cctld.co.
> co.172800  INNSns6.cctld.co.
> co.172800  INNSns4.cctld.co.
> co.172800  INNSns3.cctld.co.
> co.172800  INNSns2.cctld.co.
>
> ;; ADDITIONAL SECTION:
> ns1.cctld.co.   172800  INA156.154.100.25
> ns2.cctld.co.   172800  INA156.154.101.25
> ns3.cctld.co.   172800  INA156.154.102.25
> ns4.cctld.co.   172800  INA156.154.103.25
> ns5.cctld.co.   172800  INA156.154.104.25
> ns6.cctld.co.   172800  INA156.154.105.25
> ns1.cctld.co.   172800  INAAAA2001:502:2eda::21
> ns2.cctld.co.   172800  INAAAA2001:502:ad09::21
> ns3.cctld.co.   172800  INAAAA2610:a1:1009::21
> ns4.cctld.co.   172800  INAAAA2610:a1:1010::21
> ns5.cctld.co.   172800  INAAAA2610:a1:1011::21
> ns6.cctld.co.   172800  INAAAA2610:a1:1012::21
>
> ;; Query time: 16 msec
> ;; SERVER: 192.112.36.4#53(192.112.36.4)
> ;; WHEN: Tue Sep 08 13:34:20 CEST 2020
> ;; MSG SIZE  rcvd: 458
>
>
> Additionally I get the resolved IPs in the trace logs (line 328
> apparently from the seconds worker thread) but not the dig output.
>
> Sep  8 12:15:33 rho pdns_recursor[25208]: [51] nameservers.dnscheck.co:
> answer is in: resolved to '52.48.61.155|A'
> Sep  8 12:15:33 rho pdns_recursor[25208]: [51] nameservers.dnscheck.co:
> answer is in: resolved to '104.236.169.228|A'
> Sep  8 12:15:33 rho pdns_recursor[25208]: [51] nameservers.dnscheck.co:
> answer is in: resolved to '104.131.72.189|A'
>
> Is this a dig timeout? Or do I only get the response from the first
> worker thread?
>
> And now I'm more confused then before. The connection from and to the
> server (SSH, etc) is rock solid.
> A iperf test shows the full gigabit connection is available.
> The server is more or less idle and has 8 cores and 32GB RAM as mostly a
> docker host with some 20-30 container (nextcloud, mailcow, ...) running
> for personal usage by me and my family.
>
> How can I check for problems with a large number of small connections?
> But this shouldn't be that much fur a single local recursor, should it?
>
> Also I don't see any network related messages in the kernel log or
> anywhere else.
> I'm not aware of any rate limits for the uplink to the provider.
>
> regards
> Chris
>
>
>
>
>
>
> Am 2020-09-08 09:33, schrieb Otto Moerbeek:
>> On Tue, Sep 08, 2020 at 09:22:31AM +0200, Christian Degenkolb wrote:
>>
>>> (send again, first answer was not send cc to the ML)
>>>
>>> Hi,
>>>
>>> sorry for not sending any configs. pdns_recursor runs more or less
>>> with the
>>> vanilla config with the following changes:
>>>
>>> forward-zones-recurse=zen.spamhaus.org=1.1.1.1;1.0.0.1 (thats why I
>>> wanted
>>> to use the local recursor, as mentioned the server is located in the
>>> hetzner
>>> IP Range which apparently is blocked for the spamhaus DNSBL)
>>> loglevel=6
>>> log-common-errors=yes
>>> quiet=no
>>> root-nx-trust=no (found this as a solution for the SERVERFAIL but did
>>> not
>>> work)
>>>
>>> and
>>> # rec_control set-carbon-server 37.252.122.50 rho-test (for the grafs)
>>>
>>>
>>> A trace for the same resolves from my last mail:
>>>
>>>  $ time dig +trace pubs.vmware.com @127.0.0.1
>>> ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> +trace pubs.vmware.com
>>> @127.0.0.1
>>> ;; global options: +cmd
>>> .                       86118   IN      NS      d.root-servers.net.
>>> .                       86118   IN      NS      c.root-servers.net.
>>> .                       86118   IN      NS      l.root-servers.net.
>>> .                       86118   IN      NS      b.root-servers.net.
>>> .                       86118   IN      NS      f.root-servers.net.
>>> .                       86118   IN      NS      m.root-servers.net.
>>> .                       86118   IN      NS      e.root-servers.net.
>>> .                       86118   IN      NS      a.root-servers.net.
>>> .                       86118   IN      NS      i.root-servers.net.
>>> .                       86118   IN      NS      k.root-servers.net.
>>> .                       86118   IN      NS      g.root-servers.net.
>>> .                       86118   IN      NS      h.root-servers.net.
>>> .                       86118   IN      NS      j.root-servers.net.
>>> .                       86118   IN      RRSIG   NS 8 0 518400
>>> 20200921050000
>>> 20200908040000 46594 .
>>> wgnBz8tKA9hjwIxmMQgTVwnZaiUpAB9a1+oC5T/syHzqNj1e5qhApLQN
>>> NLok43hu5Ykt8RFe/IiDZuYxIdyyzItwk
>>> 4QN8xNgsQsfhVfBbZ26bWRz
>>> fskquwnFn6Gmvq2qI6o42tsBxXUw09X4sNlNYI2zHB3sKaaMu0AbN9WI
>>> Pe14jpX/PwaP3m78+XqMy9CiKmuDon6g3BuyecPhCZL5Pa8ZPC7nrKfV
>>> pfyNSiPoBODsJE96UHGlOCJTFcbu/6Ia4ek3AGOJf+WC84HPrxLT
>>> riyk XHfbPl7EjTbFSPgT8D7jGBfVCTQU3JSfynv29VFAHWZu1gm5VJWNQGaw u5gatA==
>>> ;; Received 540 bytes from 127.0.0.1#53(127.0.0.1) in 0 ms
>>>
>>> com.                    172800  IN      NS      a.gtld-servers.net.
>>> com.                    172800  IN      NS      b.gtld-servers.net.
>>> com.                    172800  IN      NS      c.gtld-servers.net.
>>> com.                    172800  IN      NS      d.gtld-servers.net.
>>> com.                    172800  IN      NS      e.gtld-servers.net.
>>> com.                    172800  IN      NS      f.gtld-servers.net.
>>> com.                    172800  IN      NS      g.gtld-servers.net.
>>> com.                    172800  IN      NS      h.gtld-servers.net.
>>> com.                    172800  IN      NS      i.gtld-servers.net.
>>> com.                    172800  IN      NS      j.gtld-servers.net.
>>> com.                    172800  IN      NS      k.gtld-servers.net.
>>> com.                    172800  IN      NS      l.gtld-servers.net.
>>> com.                    172800  IN      NS      m.gtld-servers.net.
>>> com.                    86400   IN      DS      30909 8 2
>>> E2D3C916F6DEEAC73294E8268FB5885044A833FC5459588F4A9184CF C41A5766
>>> com.                    86400   IN      RRSIG   DS 8 1 86400
>>> 20200921050000
>>> 20200908040000 46594 .
>>> zz85z6R/YUHxyW+ywA6zrgiYILjPo0i248M3wU+2XCRCneBH6yknQfjM
>>> LIcbo3vADVUlkJd0l4W2TLd7NPgC255hr2
>>> +ALojzzHa07jyFmE203Kdw
>>> ma7XL0C55TdFrCEMhARkZf4EncfJH9JH+fdWRWdMr0EQZd1A+FzMYemO
>>> o7/L/8ZYq4FOt0vz+zheAJNDveGii+QpXAoDyw4xt3HMUVM+40Z/VgD1
>>> tk9Y3K9e2wwRNISeHdlq21JFVA2SY/gDgPCzBtM1r9Yz7oFZ2ld5W
>>> AD0 P84GPEUMgUceAGofwxlV9+dSawhunskb+yVrpdjpizLageyJRWEu/F9A zDXxew==
>>> ;; Received 1175 bytes from 198.97.190.53#53(h.root-servers.net) in 5 ms
>>>
>>> vmware.com.             172800  IN      NS      dns1.p05.nsone.net.
>>> vmware.com.             172800  IN      NS      dns2.p05.nsone.net.
>>> vmware.com.             172800  IN      NS      dns3.p05.nsone.net.
>>> vmware.com.             172800  IN      NS      dns4.p05.nsone.net.
>>> vmware.com.             172800  IN      NS      ns01.vmwdns.com.
>>> vmware.com.             172800  IN      NS      ns02.vmwdns.com.
>>> vmware.com.             172800  IN      NS      ns03.vmwdns.com.
>>> vmware.com.             172800  IN      NS      ns04.vmwdns.com.
>>> vmware.com.             86400   IN      DS      48553 13 2
>>> AA2C697F3990472642AF01509A18224828E403CA8608EC75D5C83002 CE21847E
>>> vmware.com.             86400   IN      RRSIG   DS 8 2 86400
>>> 20200915062203
>>> 20200908051203 24966 com.
>>> FA2xsJKvT2LLn5UEy7hAE7PaYmds7FBkQB0SGhm8riwJRKnxbHAY0tvv
>>> I1T/k0EzXJ4wy1J5qzNLMjhzFgPxEQB
>>> 6BwBfJm8qo8Cnzxm4YC5Ko1/9
>>> pDWooVBHoFfMmJgu14Dk+u1AcHobxH9pPs7az16cLK/3YeaFW3dCrIVQ
>>> NK2fZc0d/pc7CY0Zl1LjYQdTq+MsZiL2kbepEHD6A/4J6g==
>>> ;; Received 523 bytes from 2001:503:eea3::30#53(g.gtld-servers.net)
>>> in 6 ms
>>>
>>> pubs.vmware.com.        30      IN      CNAME
>>> pubs.vmware.com.ds.edgekey.net.
>>> pubs.vmware.com.        30      IN      RRSIG   CNAME 13 3 30
>>> 20200909071011
>>> 20200907071011 12752 vmware.com.
>>> yTxj4OFvCx3flxtOFAFdkwAOpOAVNibgseFi5U5ekzYbdATw98xZqrDT
>>> tYs/n46iHFiLN4ql4Y3MS6U
>>> 16Qr6DQ==
>>> ;; Received 194 bytes from 45.54.11.1#53(ns01.vmwdns.com) in 11 ms
>>>
>>> real0m32.149s
>>> user0m0.012s
>>> sys0m0.012s
>>>
>>> But this looks normal to me. I don't know why the trace only shows 5,
>>> 6 and
>>> 11 ms but takes up to 32 seconds to finish.
>>
>> Well, that is suspect, but see below.
>>
>>>
>>> Regarding your questions for the ipv6 connectivity. How can I test this?
>>
>> Run pdns_recursor with the --trace option (or trace=yes in the config
>> file), do some queries and look at the results in the log file. Now
>> the recursor logs a lot in trace mode, so take your time trying to
>> understand what is going on. Members of this list can likely help if
>> you do not spot anything.
>>
>>     -Otto
>>
>>>
>>> I did a
>>>
>>> $ dig ipv6.google.com @127.0.0.1
>>>
>>> ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> ipv6.google.com @127.0.0.1
>>> ;; global options: +cmd
>>> ;; Got answer:
>>> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9226
>>> ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1
>>>
>>> ;; OPT PSEUDOSECTION:
>>> ; EDNS: version: 0, flags:; udp: 4096
>>> ;; QUESTION SECTION:
>>> ;ipv6.google.com.INA
>>>
>>> ;; ANSWER SECTION:
>>> ipv6.google.com.86400   INCNAME   ipv6.l.google.com.
>>>
>>> ;; AUTHORITY SECTION:
>>> l.google.com.   60INSOAns1.google.com. dns-admin.google.com.
>>> 330353109 900
>>> 900 1800 60
>>>
>>> ;; Query time: 3087 msec
>>> ;; SERVER: 127.0.0.1#53(127.0.0.1)
>>> ;; WHEN: Tue Sep 08 09:12:50 CEST 2020
>>> ;; MSG SIZE  rcvd: 115
>>>
>>> and
>>>
>>> $ ping6 ipv6.google.com
>>> PING ipv6.google.com(fra16s13-in-x0e.1e100.net
>>> (2a00:1450:4001:819::200e))
>>> 56 data bytes
>>> 64 bytes from fra16s13-in-x0e.1e100.net (2a00:1450:4001:819::200e):
>>> icmp_seq=1 ttl=118 time=5.11 ms
>>> 64 bytes from fra16s13-in-x0e.1e100.net (2a00:1450:4001:819::200e):
>>> icmp_seq=2 ttl=118 time=5.08 ms
>>> 64 bytes from fra16s13-in-x0e.1e100.net (2a00:1450:4001:819::200e):
>>> icmp_seq=3 ttl=118 time=5.12 ms
>>> 64 bytes from fra16s13-in-x0e.1e100.net (2a00:1450:4001:819::200e):
>>> icmp_seq=4 ttl=118 time=5.13 ms
>>> 64 bytes from fra16s13-in-x0e.1e100.net (2a00:1450:4001:819::200e):
>>> icmp_seq=5 ttl=118 time=5.09 ms
>>> 64 bytes from fra16s13-in-x0e.1e100.net (2a00:1450:4001:819::200e):
>>> icmp_seq=6 ttl=118 time=5.08 ms
>>> 64 bytes from fra16s13-in-x0e.1e100.net (2a00:1450:4001:819::200e):
>>> icmp_seq=7 ttl=118 time=5.08 ms
>>> ^C
>>> --- ipv6.google.com ping statistics ---
>>> 7 packets transmitted, 7 received, 0% packet loss, time 24ms
>>> rtt min/avg/max/mdev = 5.075/5.096/5.133/0.043 ms
>>>
>>> and it looks good.
>>>
>>> regards
>>> Chris
>>>
>>>
>>> Am 2020-09-04 15:05, schrieb Otto Moerbeek:
>>> > On Wed, Sep 02, 2020 at 09:44:37AM +0200, Christian Degenkolb via
>>> > Pdns-users wrote:
>>> >
>>> > > Hi,
>>> > >
>>> > > I hope somebody on the ML can help me figure out what I'm doing
>>> wrong.
>>> > > I have a local pdns_recursor (version 4.1.11-1+deb10u1 from
>>> debian 10)
>>> > > runing and added it at the top of my /etc/resolve.conf as 127.0.0.1.
>>> > >
>>> > > However I see some strange SERVERFAIL resolves happening and all in
>>> > > all a
>>> > > slow DNS system.
>>> > >
>>> > > For example see the following two consecutive resolves and a direct
>>> > > request
>>> > > to the NS.
>>> > > The first one takes nearly 3 seconds vs 11 ms from the same system
>>> > > if I
>>> > > query the NS directly.
>>> > >
>>> > > $ dig pubs.vmware.com @127.0.0.1
>>> > >
>>> > > ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> pubs.vmware.com
>>> > > @127.0.0.1
>>> > > ;; global options: +cmd
>>> > > ;; Got answer:
>>> > > ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 4929
>>> > > ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
>>> > >
>>> > > ;; OPT PSEUDOSECTION:
>>> > > ; EDNS: version: 0, flags:; udp: 4096
>>> > > ;; QUESTION SECTION:
>>> > > ;pubs.vmware.com.INA
>>> > >
>>> > > ;; ANSWER SECTION:
>>> > > pubs.vmware.com.30INCNAME   pubs.vmware.com.ds.edgekey.net.
>>> > > pubs.vmware.com.ds.edgekey.net. 10 IN   CNAME
>>> > > e751.dscx.akamaiedge.net.
>>> > >
>>> > > ;; Query time: 3009 msec
>>> > > ;; SERVER: 127.0.0.1#53(127.0.0.1)
>>> > > ;; WHEN: Wed Sep 02 09:19:04 CEST 2020
>>> > > ;; MSG SIZE  rcvd: 123
>>> > >
>>> > > $ dig pubs.vmware.com @127.0.0.1
>>> > >
>>> > > ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> pubs.vmware.com
>>> > > @127.0.0.1
>>> > > ;; global options: +cmd
>>> > > ;; Got answer:
>>> > > ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1345
>>> > > ;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
>>> > >
>>> > > ;; OPT PSEUDOSECTION:
>>> > > ; EDNS: version: 0, flags:; udp: 4096
>>> > > ;; QUESTION SECTION:
>>> > > ;pubs.vmware.com.INA
>>> > >
>>> > > ;; ANSWER SECTION:
>>> > > pubs.vmware.com.18INCNAME   pubs.vmware.com.ds.edgekey.net.
>>> > > pubs.vmware.com.ds.edgekey.net. 4 INCNAME
>>> e751.dscx.akamaiedge.net.
>>> > > e751.dscx.akamaiedge.net. 16INA104.111.214.47
>>> > >
>>> > > ;; Query time: 0 msec
>>> > > ;; SERVER: 127.0.0.1#53(127.0.0.1)
>>> > > ;; WHEN: Wed Sep 02 09:19:08 CEST 2020
>>> > > ;; MSG SIZE  rcvd: 139
>>> > >
>>> > > $ dig pubs.vmware.com @ns03.vmwdns.com
>>> > >
>>> > > ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> pubs.vmware.com
>>> > > @ns03.vmwdns.com
>>> > > ;; global options: +cmd
>>> > > ;; Got answer:
>>> > > ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 5509
>>> > > ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
>>> > > ;; WARNING: recursion requested but not available
>>> > >
>>> > > ;; OPT PSEUDOSECTION:
>>> > > ; EDNS: version: 0, flags:; udp: 4096
>>> > > ;; QUESTION SECTION:
>>> > > ;pubs.vmware.com.INA
>>> > >
>>> > > ;; ANSWER SECTION:
>>> > > pubs.vmware.com.30INCNAME   pubs.vmware.com.ds.edgekey.net.
>>> > >
>>> > > ;; Query time: 11 msec
>>> > > ;; SERVER: 45.54.11.129#53(45.54.11.129)
>>> > > ;; WHEN: Wed Sep 02 09:34:42 CEST 2020
>>> > > ;; MSG SIZE  rcvd: 88
>>> > >
>>> > > Also I have a number SERVFAIL in /var/log/syslog (pdns_recurser is
>>> > > currently
>>> > > running with loglevel=6).
>>> > > For example:
>>> > >
>>> > > Sep  2 08:45:35 rho pdns_recursor[19311]: Sending SERVFAIL to
>>> > > 127.0.0.1
>>> > > during resolve of 'pubs.vmware.com' because: Too much time
>>> waiting for
>>> > > pubs.vmware.com.ds.edgekey.net|A, timeouts: 5,
>>> > > throttles: 1, queries: 6, 7991msec
>>> > >
>>> > > # grep 'Too much time waiting for' /var/log/syslog | wc -l
>>> > > 184
>>> > >
>>> > > As per
>>> > > https://blog.powerdns.com/2014/12/11/powerdns-graphing-as-a-service/
>>> > > I send the metrics to
>>> https://metronome1.powerdns.com/?server=pdns.rho-test.recursor&beginTime=-172800
>>>
>>> > >
>>> > > Does anybody have an idea whats wrong? This seems way to slow for
>>> > > DNS and
>>> > > the SERVFAIL schouldn't happen this often.
>>> > > The server in question is running in a DC of the german Hoster
>>> > > hetzner.de.
>>> > > Besides the strange DNS I don't have any problems with the
>>> > > reliability of
>>> > > the network connection.
>>> > >
>>> > > thanks
>>> > > Chris
>>> > >
>>> > > _______________________________________________
>>> > > Pdns-users mailing list
>>> > > Pdns-users at mailman.powerdns.com
>>> > > https://mailman.powerdns.com/mailman/listinfo/pdns-users
>>> >
>>> > You did not share any config or traces, so it's hard to tell. A wild
>>> > guess: It might be you enabled IPV6 but your IPV6 connectivity is bad.
>>> >
>>> >     -Otto
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