coredns: [ERROR] plugin/errors: 2 me.com. MX: dns: overflow unpacking uint16
- the version of CoreDNS you are using 1.3.1
- your Corefile Azure AKS
Corefile:
.:53 {
errors
health
kubernetes cluster.local in-addr.arpa ip6.arpa {
pods insecure
upstream
fallthrough in-addr.arpa ip6.arpa
}
prometheus :9153
forward . /etc/resolv.conf
cache 30
loop
reload
loadbalance
import custom/*.override
}
- logs, if applicable
10-10T13:41:50.736Z [INFO] plugin/reload: Running configuration MD5 = d8c69602fc5a3428908dc8f34f9aae58
2019-10-10T13:47:49.441Z [ERROR] plugin/errors: 2 me.com. MX: read udp 10.240.0.13:49706->168.63.129.16:53: i/o timeout
2019-10-10T13:56:33.713Z [ERROR] plugin/errors: 2 me.com. MX: dns: overflow unpacking uint16
2019-10-10T13:58:27.887Z [ERROR] plugin/errors: 2 me.com. MX: dns: overflow unpacking uint16
2019-10-10T14:04:06.415Z [ERROR] plugin/errors: 2 me.com. MX: dns: overflow unpacking uint16
[WARNING] No files matching import glob pattern: custom/*.override
[WARNING] No files matching import glob pattern: custom/*.server
.:53
2019-10-10T13:41:50.776Z [INFO] CoreDNS-1.3.1
2019-10-10T13:41:50.776Z [INFO] linux/amd64, go1.11.4, 6b56a9c
CoreDNS-1.3.1
linux/amd64, go1.11.4, 6b56a9c
2019-10-10T13:41:50.776Z [INFO] plugin/reload: Running configuration MD5 = d8c69602fc5a3428908dc8f34f9aae58
2019-10-10T13:47:25.505Z [ERROR] plugin/errors: 2 me.com. MX: dns: overflow unpacking uint16
2019-10-10T13:55:07.068Z [ERROR] plugin/errors: 2 me.com. MX: read udp 10.240.0.22:37383->168.63.129.16:53: i/o timeout
2019-10-10T14:04:13.854Z [ERROR] plugin/errors: 2 me.com. MX: read udp 10.240.0.22:41684->168.63.129.16:53: i/o timeout
When we are trying to resolve mx records for example:
me.com icloud.com
using nslookup, we get the below error:
root@mynginx-66f8579864-pcqbr:/# nslookup -q=mx icloud.com
Server: 10.0.0.10
Address: 10.0.0.10#53
** server can't find icloud.com: SERVFAIL
root@mynginx-66f8579864-pcqbr:/#
- using dig it works fine
root@mynginx-66f8579864-pcqbr:/# dig icloud.com mx
; <<>> DiG 9.11.5-P4-5.1-Debian <<>> icloud.com mx
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26680
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 49
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;icloud.com. IN MX
;; ANSWER SECTION:
icloud.com. 30 IN MX 10 mx5.mail.icloud.com.
icloud.com. 30 IN MX 10 mx4.mail.icloud.com.
icloud.com. 30 IN MX 10 mx6.mail.icloud.com.
icloud.com. 30 IN MX 10 mx3.mail.icloud.com.
icloud.com. 30 IN MX 10 mx1.mail.icloud.com.
icloud.com. 30 IN MX 10 mx2.mail.icloud.com.
;; ADDITIONAL SECTION:
mx5.mail.icloud.com. 30 IN A 17.57.8.138
mx3.mail.icloud.com. 30 IN A 17.57.8.136
mx5.mail.icloud.com. 30 IN A 17.133.229.11
mx3.mail.icloud.com. 30 IN A 17.57.8.141
mx6.mail.icloud.com. 30 IN A 17.57.8.144
mx2.mail.icloud.com. 30 IN A 17.178.102.83
mx2.mail.icloud.com. 30 IN A 17.57.8.140
mx1.mail.icloud.com. 30 IN A 17.178.102.82
mx6.mail.icloud.com. 30 IN A 17.172.34.70
mx2.mail.icloud.com. 30 IN A 17.172.34.11
mx2.mail.icloud.com. 30 IN A 17.178.102.79
mx2.mail.icloud.com. 30 IN A 17.142.163.14
mx5.mail.icloud.com. 30 IN A 17.133.229.13
mx6.mail.icloud.com. 30 IN A 17.133.229.12
mx5.mail.icloud.com. 30 IN A 17.178.97.78
mx2.mail.icloud.com. 30 IN A 17.142.163.11
mx1.mail.icloud.com. 30 IN A 17.172.34.10
mx2.mail.icloud.com. 30 IN A 17.57.8.135
mx3.mail.icloud.com. 30 IN A 17.172.34.65
mx5.mail.icloud.com. 30 IN A 17.172.34.68
mx1.mail.icloud.com. 30 IN A 17.57.8.139
mx4.mail.icloud.com. 30 IN A 17.133.229.9
mx4.mail.icloud.com. 30 IN A 17.57.8.142
mx1.mail.icloud.com. 30 IN A 17.142.163.10
mx4.mail.icloud.com. 30 IN A 17.57.8.137
mx3.mail.icloud.com. 30 IN A 17.178.97.76
mx3.mail.icloud.com. 30 IN A 17.178.97.72
mx6.mail.icloud.com. 30 IN A 17.172.34.71
mx1.mail.icloud.com. 30 IN A 17.178.102.78
mx1.mail.icloud.com. 30 IN A 17.57.8.134
mx4.mail.icloud.com. 30 IN A 17.172.34.66
mx3.mail.icloud.com. 30 IN A 17.142.163.12
mx4.mail.icloud.com. 30 IN A 17.133.229.8
mx1.mail.icloud.com. 30 IN A 17.142.163.13
mx4.mail.icloud.com. 30 IN A 17.178.97.77
mx6.mail.icloud.com. 30 IN A 17.133.229.14
mx5.mail.icloud.com. 30 IN A 17.57.8.143
mx6.mail.icloud.com. 30 IN A 17.178.97.79
mx5.mail.icloud.com. 30 IN A 17.178.97.74
mx2.mail.icloud.com. 30 IN A 17.172.34.12
mx6.mail.icloud.com. 30 IN A 17.57.8.133
mx4.mail.icloud.com. 30 IN A 17.172.34.67
mx3.mail.icloud.com. 30 IN A 17.142.163.15
mx4.mail.icloud.com. 30 IN A 17.178.97.73
mx6.mail.icloud.com. 30 IN A 17.178.97.75
mx3.mail.icloud.com. 30 IN A 17.172.34.64
mx1.mail.icloud.com. 30 IN A 17.172.34.9
mx5.mail.icloud.com. 30 IN A 17.172.34.69
;; Query time: 1 msec
;; SERVER: 10.0.0.10#53(10.0.0.10)
;; WHEN: Thu Oct 10 14:44:35 UTC 2019
;; MSG SIZE rcvd: 932
root@mynginx-66f8579864-pcqbr:/#
However, if we immediately after dig command tried nslookup it will work ( I guess this is because it will be cached).
I got a network trace and I can see that both me.com and icloud.com has packet size of 970.
- The issue can be mitigated by adding custom core file with a proxy
apiVersion: v1
kind: ConfigMap
metadata:
name: coredns-custom
namespace: kube-system
data:
test.server: |
me.com:53 {
errors
cache 30
proxy . 8.8.8.8
}
Wondering if this is a bug ? this looks similar to https://github.com/coredns/coredns/issues/2224 but that one seems to be resolved for A records only ?
About this issue
- Original URL
- State: closed
- Created 5 years ago
- Comments: 24 (10 by maintainers)
Hi @chrisohaver - I tested with AKS running coredns 1.6.4 and still the same issue:
I am also using official image coredns/coredns:1.6.4