[Bug 1818217] Re: Systemd Resolve cache handling issues

Abam 1818217 at bugs.launchpad.net
Mon Mar 4 14:57:24 UTC 2019


** Description changed:

  I am facing really strange issues with systemd-resolved.
- 
  
  Local cache of DNS replies seems to be unreliable.
  
  For example, when a try to get ANY record for github.com, I get A, AAAA,
  MX, CAA, TXT and NS records.
  
- When the TTL of entries expires, the same request is this ignoring them.
+ When the TTL of entries expires, the same request is just ignoring them.
  The result is getting narrowed.
- 
  
  First try:
  
  dig ANY github.com
  
  ; <<>> DiG 9.11.3-1ubuntu1.5-Ubuntu <<>> ANY github.com
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4140
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 18, AUTHORITY: 0, ADDITIONAL: 1
  
  ;; OPT PSEUDOSECTION:
  ; EDNS: version: 0, flags:; udp: 65494
  ;; QUESTION SECTION:
  ;github.com.			IN	ANY
  
  ;; ANSWER SECTION:
  github.com.		227	IN	SOA	ns-1707.awsdns-21.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
  github.com.		2927	IN	MX	10 alt4.aspmx.l.google.com.
  github.com.		2927	IN	MX	1 aspmx.l.google.com.
  github.com.		2927	IN	MX	5 alt1.aspmx.l.google.com.
  github.com.		2927	IN	MX	5 alt2.aspmx.l.google.com.
  github.com.		2927	IN	MX	10 alt3.aspmx.l.google.com.
  github.com.		2927	IN	TXT	"MS=6BF03E6AF5CB689E315FB6199603BABF2C88D805"
  github.com.		2927	IN	TXT	"docusign=087098e3-3d46-47b7-9b4e-8a23028154cd"
  github.com.		2927	IN	TXT	"v=spf1 ip4:192.30.252.0/22 ip4:208.74.204.0/22 ip4:46.19.168.0/23 include:_spf.google.com include:esp.github.com include:_spf.createsend.com include:servers.mcsv.net ~all"
  github.com.		2927	IN	TXT	"MS=ms44452932"
  github.com.		227	IN	NS	ns-421.awsdns-52.com.
  github.com.		227	IN	NS	ns4.p16.dynect.net.
  github.com.		227	IN	NS	ns3.p16.dynect.net.
  github.com.		227	IN	NS	ns-1707.awsdns-21.co.uk.
  github.com.		227	IN	NS	ns2.p16.dynect.net.
  github.com.		227	IN	NS	ns1.p16.dynect.net.
  github.com.		227	IN	NS	ns-520.awsdns-01.net.
  github.com.		227	IN	NS	ns-1283.awsdns-32.org.
  
  ;; Query time: 9 msec
  ;; SERVER: 127.0.0.53#53(127.0.0.53)
  ;; WHEN: Fri Mar 01 12:13:58 CET 2019
  ;; MSG SIZE  rcvd: 758
  
- 
  Second try (A records are now missing):
  
  dig ANY github.com
  
  ; <<>> DiG 9.11.3-1ubuntu1.5-Ubuntu <<>> ANY github.com
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42356
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 18, AUTHORITY: 0, ADDITIONAL: 1
  
  ;; OPT PSEUDOSECTION:
  ; EDNS: version: 0, flags:; udp: 65494
  ;; QUESTION SECTION:
  ;github.com.			IN	ANY
  
  ;; ANSWER SECTION:
  github.com.		30	IN	SOA	ns-1707.awsdns-21.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
  github.com.		2730	IN	MX	5 alt2.aspmx.l.google.com.
  github.com.		2730	IN	MX	10 alt3.aspmx.l.google.com.
  github.com.		2730	IN	MX	10 alt4.aspmx.l.google.com.
  github.com.		2730	IN	MX	1 aspmx.l.google.com.
  github.com.		2730	IN	MX	5 alt1.aspmx.l.google.com.
  github.com.		2730	IN	TXT	"v=spf1 ip4:192.30.252.0/22 ip4:208.74.204.0/22 ip4:46.19.168.0/23 include:_spf.google.com include:esp.github.com include:_spf.createsend.com include:servers.mcsv.net ~all"
  github.com.		2730	IN	TXT	"MS=ms44452932"
  github.com.		2730	IN	TXT	"MS=6BF03E6AF5CB689E315FB6199603BABF2C88D805"
  github.com.		2730	IN	TXT	"docusign=087098e3-3d46-47b7-9b4e-8a23028154cd"
  github.com.		30	IN	NS	ns1.p16.dynect.net.
  github.com.		30	IN	NS	ns-421.awsdns-52.com.
  github.com.		30	IN	NS	ns2.p16.dynect.net.
  github.com.		30	IN	NS	ns4.p16.dynect.net.
  github.com.		30	IN	NS	ns-1707.awsdns-21.co.uk.
  github.com.		30	IN	NS	ns-1283.awsdns-32.org.
  github.com.		30	IN	NS	ns-520.awsdns-01.net.
  github.com.		30	IN	NS	ns3.p16.dynect.net.
  
  ;; Query time: 8 msec
  ;; SERVER: 127.0.0.53#53(127.0.0.53)
  ;; WHEN: Fri Mar 01 12:17:15 CET 2019
  ;; MSG SIZE  rcvd: 758
  
- 
  Third try (No more NS) :
  
  dig ANY github.com
  
  ; <<>> DiG 9.11.3-1ubuntu1.5-Ubuntu <<>> ANY github.com
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 34183
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 9, AUTHORITY: 0, ADDITIONAL: 1
  
  ;; OPT PSEUDOSECTION:
  ; EDNS: version: 0, flags:; udp: 65494
  ;; QUESTION SECTION:
  ;github.com.			IN	ANY
  
  ;; ANSWER SECTION:
  github.com.		2688	IN	MX	10 alt4.aspmx.l.google.com.
  github.com.		2688	IN	MX	1 aspmx.l.google.com.
  github.com.		2688	IN	MX	5 alt1.aspmx.l.google.com.
  github.com.		2688	IN	MX	5 alt2.aspmx.l.google.com.
  github.com.		2688	IN	MX	10 alt3.aspmx.l.google.com.
  github.com.		2688	IN	TXT	"MS=ms44452932"
  github.com.		2688	IN	TXT	"MS=6BF03E6AF5CB689E315FB6199603BABF2C88D805"
  github.com.		2688	IN	TXT	"docusign=087098e3-3d46-47b7-9b4e-8a23028154cd"
  github.com.		2688	IN	TXT	"v=spf1 ip4:192.30.252.0/22 ip4:208.74.204.0/22 ip4:46.19.168.0/23 include:_spf.google.com include:esp.github.com include:_spf.createsend.com include:servers.mcsv.net ~all"
  
  ;; Query time: 3 msec
  ;; SERVER: 127.0.0.53#53(127.0.0.53)
  ;; WHEN: Fri Mar 01 12:17:57 CET 2019
  ;; MSG SIZE  rcvd: 477
  
  And so on.
  
  
- That's not the only bug that I have noticed. If I look for an non existing record, the response is cached. And any legit request is this ignored. See https://github.com/systemd/systemd/issues/11789 for more details.
- 
- 
- Try to resolv github.com CNAME record dig CNAME github.com
- 
- This will return an empty result.
- 
- Then try to resolve github.com A record dig A github.com.
- 
- This will now return empty result unless you restart systemd-resolved or
- wait for cache expiration.
- 
- 
  systemd version the issue has been seen with
  Installed: 237-3ubuntu10.13
  Used distribution
  
  Distributor ID: Ubuntu
  Description: Ubuntu 18.04.2 LTS
  Release: 18.04
  Codename: bionic
  
+ dnsutils version
  
- Note: I am facing the same issues in ubuntu 16.04 with systemd 229-4ubuntu21.2.
+ 9.11.3+dfsg-1ubuntu1.5
+ 
+ 
+ Note: I am facing the same issues in ubuntu 16.04 with systemd
+ 229-4ubuntu21.2.

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https://bugs.launchpad.net/bugs/1818217

Title:
  Bind9 cache handling issues for dig  ANY request

Status in systemd package in Ubuntu:
  New

Bug description:
  I am facing really strange issues with systemd-resolved.

  Local cache of DNS replies seems to be unreliable.

  For example, when a try to get ANY record for github.com, I get A,
  AAAA, MX, CAA, TXT and NS records.

  When the TTL of entries expires, the same request is just ignoring
  them. The result is getting narrowed.

  First try:

  dig ANY github.com

  ; <<>> DiG 9.11.3-1ubuntu1.5-Ubuntu <<>> ANY github.com
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4140
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 18, AUTHORITY: 0, ADDITIONAL: 1

  ;; OPT PSEUDOSECTION:
  ; EDNS: version: 0, flags:; udp: 65494
  ;; QUESTION SECTION:
  ;github.com.			IN	ANY

  ;; ANSWER SECTION:
  github.com.		227	IN	SOA	ns-1707.awsdns-21.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
  github.com.		2927	IN	MX	10 alt4.aspmx.l.google.com.
  github.com.		2927	IN	MX	1 aspmx.l.google.com.
  github.com.		2927	IN	MX	5 alt1.aspmx.l.google.com.
  github.com.		2927	IN	MX	5 alt2.aspmx.l.google.com.
  github.com.		2927	IN	MX	10 alt3.aspmx.l.google.com.
  github.com.		2927	IN	TXT	"MS=6BF03E6AF5CB689E315FB6199603BABF2C88D805"
  github.com.		2927	IN	TXT	"docusign=087098e3-3d46-47b7-9b4e-8a23028154cd"
  github.com.		2927	IN	TXT	"v=spf1 ip4:192.30.252.0/22 ip4:208.74.204.0/22 ip4:46.19.168.0/23 include:_spf.google.com include:esp.github.com include:_spf.createsend.com include:servers.mcsv.net ~all"
  github.com.		2927	IN	TXT	"MS=ms44452932"
  github.com.		227	IN	NS	ns-421.awsdns-52.com.
  github.com.		227	IN	NS	ns4.p16.dynect.net.
  github.com.		227	IN	NS	ns3.p16.dynect.net.
  github.com.		227	IN	NS	ns-1707.awsdns-21.co.uk.
  github.com.		227	IN	NS	ns2.p16.dynect.net.
  github.com.		227	IN	NS	ns1.p16.dynect.net.
  github.com.		227	IN	NS	ns-520.awsdns-01.net.
  github.com.		227	IN	NS	ns-1283.awsdns-32.org.

  ;; Query time: 9 msec
  ;; SERVER: 127.0.0.53#53(127.0.0.53)
  ;; WHEN: Fri Mar 01 12:13:58 CET 2019
  ;; MSG SIZE  rcvd: 758

  Second try (A records are now missing):

  dig ANY github.com

  ; <<>> DiG 9.11.3-1ubuntu1.5-Ubuntu <<>> ANY github.com
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42356
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 18, AUTHORITY: 0, ADDITIONAL: 1

  ;; OPT PSEUDOSECTION:
  ; EDNS: version: 0, flags:; udp: 65494
  ;; QUESTION SECTION:
  ;github.com.			IN	ANY

  ;; ANSWER SECTION:
  github.com.		30	IN	SOA	ns-1707.awsdns-21.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
  github.com.		2730	IN	MX	5 alt2.aspmx.l.google.com.
  github.com.		2730	IN	MX	10 alt3.aspmx.l.google.com.
  github.com.		2730	IN	MX	10 alt4.aspmx.l.google.com.
  github.com.		2730	IN	MX	1 aspmx.l.google.com.
  github.com.		2730	IN	MX	5 alt1.aspmx.l.google.com.
  github.com.		2730	IN	TXT	"v=spf1 ip4:192.30.252.0/22 ip4:208.74.204.0/22 ip4:46.19.168.0/23 include:_spf.google.com include:esp.github.com include:_spf.createsend.com include:servers.mcsv.net ~all"
  github.com.		2730	IN	TXT	"MS=ms44452932"
  github.com.		2730	IN	TXT	"MS=6BF03E6AF5CB689E315FB6199603BABF2C88D805"
  github.com.		2730	IN	TXT	"docusign=087098e3-3d46-47b7-9b4e-8a23028154cd"
  github.com.		30	IN	NS	ns1.p16.dynect.net.
  github.com.		30	IN	NS	ns-421.awsdns-52.com.
  github.com.		30	IN	NS	ns2.p16.dynect.net.
  github.com.		30	IN	NS	ns4.p16.dynect.net.
  github.com.		30	IN	NS	ns-1707.awsdns-21.co.uk.
  github.com.		30	IN	NS	ns-1283.awsdns-32.org.
  github.com.		30	IN	NS	ns-520.awsdns-01.net.
  github.com.		30	IN	NS	ns3.p16.dynect.net.

  ;; Query time: 8 msec
  ;; SERVER: 127.0.0.53#53(127.0.0.53)
  ;; WHEN: Fri Mar 01 12:17:15 CET 2019
  ;; MSG SIZE  rcvd: 758

  Third try (No more NS) :

  dig ANY github.com

  ; <<>> DiG 9.11.3-1ubuntu1.5-Ubuntu <<>> ANY github.com
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 34183
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 9, AUTHORITY: 0, ADDITIONAL: 1

  ;; OPT PSEUDOSECTION:
  ; EDNS: version: 0, flags:; udp: 65494
  ;; QUESTION SECTION:
  ;github.com.			IN	ANY

  ;; ANSWER SECTION:
  github.com.		2688	IN	MX	10 alt4.aspmx.l.google.com.
  github.com.		2688	IN	MX	1 aspmx.l.google.com.
  github.com.		2688	IN	MX	5 alt1.aspmx.l.google.com.
  github.com.		2688	IN	MX	5 alt2.aspmx.l.google.com.
  github.com.		2688	IN	MX	10 alt3.aspmx.l.google.com.
  github.com.		2688	IN	TXT	"MS=ms44452932"
  github.com.		2688	IN	TXT	"MS=6BF03E6AF5CB689E315FB6199603BABF2C88D805"
  github.com.		2688	IN	TXT	"docusign=087098e3-3d46-47b7-9b4e-8a23028154cd"
  github.com.		2688	IN	TXT	"v=spf1 ip4:192.30.252.0/22 ip4:208.74.204.0/22 ip4:46.19.168.0/23 include:_spf.google.com include:esp.github.com include:_spf.createsend.com include:servers.mcsv.net ~all"

  ;; Query time: 3 msec
  ;; SERVER: 127.0.0.53#53(127.0.0.53)
  ;; WHEN: Fri Mar 01 12:17:57 CET 2019
  ;; MSG SIZE  rcvd: 477

  And so on.

  
  systemd version the issue has been seen with
  Installed: 237-3ubuntu10.13
  Used distribution

  Distributor ID: Ubuntu
  Description: Ubuntu 18.04.2 LTS
  Release: 18.04
  Codename: bionic

  dnsutils version

  9.11.3+dfsg-1ubuntu1.5


  Note: I am facing the same issues in ubuntu 16.04 with systemd
  229-4ubuntu21.2.

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