Bug 1967766 - DNS SRV request which worked in 4.7.9 stopped working in 4.7.11
Summary: DNS SRV request which worked in 4.7.9 stopped working in 4.7.11
Alias: None
Product: OpenShift Container Platform
Classification: Red Hat
Component: Networking
Version: 4.6
Hardware: All
OS: All
Target Milestone: ---
: 4.7.z
Assignee: Stephen Greene
QA Contact: Hongan Li
: Partner1970577 1970889 (view as bug list)
Depends On: 1966116
Blocks: 1970140
TreeView+ depends on / blocked
Reported: 2021-06-03 20:37 UTC by OpenShift BugZilla Robot
Modified: 2023-01-16 07:32 UTC (History)
8 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Cause: The fix for Bug 1953097 enabled the CoreDNS Bufsize plugin with a size of 1232 bytes. Some primitive DNS resolvers are not capable of receiving DNS response messages over UDP that are greater than 512 bytes. Note that DNS resolvers that retry lookups using TCP (such as Dig) are not affected by this bug. Consequence: Some DNS resolvers (such as Go's internal DNS library) are unable to receive long-winded DNS responses from openshift-dns. Fix: Set the CoreDNS bufsize to 512 bytes for all servers. Result: DNS Clients that require UDP DNS messages to not exceed 512 bytes function as expected.
Clone Of:
Last Closed: 2021-06-29 04:19:45 UTC
Target Upstream Version:

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Github openshift cluster-dns-operator pull 277 0 None open [release-4.7] Bug 1967766: Corefile: Set bufsize to 512 bytes for all servers 2021-06-04 14:10:57 UTC
Red Hat Product Errata RHBA-2021:2502 0 None None None 2021-06-29 04:20:08 UTC

Comment 1 Hongan Li 2021-06-07 02:15:07 UTC
Verified with 4.7.0-0.ci.test-2021-06-07-011518-ci-ln-435xggk-latest on a cluster launched by cluster-bot and passed.

$ oc get clusterversion
NAME      VERSION                                                  AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.7.0-0.ci.test-2021-06-07-011518-ci-ln-435xggk-latest   True        False         25m     Cluster version is 4.7.0-0.ci.test-2021-06-07-011518-ci-ln-435xggk-latest

$ oc -n openshift-dns get cm/dns-default -oyaml
apiVersion: v1
  Corefile: |
    # test
    mytest.ocp:5353 {
        forward .
        bufsize 512
    .:5353 {
        bufsize 512
        health {
            lameduck 20s

Comment 3 Hongan Li 2021-06-10 11:41:39 UTC
PR has been merged into 4.7.0-0.nightly-2021-06-09-233032, moving to verified

Comment 4 Miciah Dashiel Butler Masters 2021-06-11 13:42:59 UTC
*** Bug 1970889 has been marked as a duplicate of this bug. ***

Comment 8 OpenShift Automated Release Tooling 2021-06-17 12:29:08 UTC
OpenShift engineering has decided to not ship Red Hat OpenShift Container Platform 4.7.17 due a regression https://bugzilla.redhat.com/show_bug.cgi?id=1973006. All the fixes which were part of 4.7.17 will be now part of 4.7.18 and planned to be available in candidate channel on June 23 2021 and in fast channel on June 28th.

Comment 12 Stephen Greene 2021-06-22 13:50:34 UTC
*** PartnerBug 1970577 has been marked as a duplicate of this bug. ***

Comment 14 errata-xmlrpc 2021-06-29 04:19:45 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (OpenShift Container Platform 4.7.18 bug fix update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.


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