Bug 1758317
| Summary: | nslookup / host do not honor the new search domain limits of glibc | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Juan Manuel Santos <jsantos> | |
| Component: | bind | Assignee: | Petr Menšík <pemensik> | |
| Status: | CLOSED WONTFIX | QA Contact: | qe-baseos-daemons | |
| Severity: | medium | Docs Contact: | Mariya Pershina <mpershin> | |
| Priority: | medium | |||
| Version: | 7.8 | CC: | fdelehay, fkrska, fweimer, knemcova, lkuprova, mpershin, pemensik, thozza | |
| Target Milestone: | rc | Keywords: | FutureFeature, Patch, Reproducer | |
| Target Release: | --- | |||
| Hardware: | Unspecified | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | Doc Type: | Known Issue | ||
| Doc Text: |
.`bind-utils` DNS lookup utilities support fewer search domains than `glibc`
The `dig`, `host`, and `nslookup` DNS lookup utilities from the `bind-utils` package support only up to 8 search domains, while the `glibc` resolver in the system supports any number of search domains. As a consequence, the DNS lookup utilities may get different results than applications when a search in the `/etc/resolv.conf` file contains more than 8 domains.
To work around this problem, use one of the following:
* Full names ending with a dot, or
* Fewer than nine domains in the `resolv.conf` search clause.
Note that it is not recommended to use more than three domains.
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Story Points: | --- | |
| Clone Of: | ||||
| : | 1816141 (view as bug list) | Environment: | ||
| Last Closed: | 2020-03-30 08:48:38 UTC | Type: | Bug | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Bug Depends On: | ||||
| Bug Blocks: | 1816141, 1821287, 1780577, 1780662 | |||
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Comment 2
Petr Menšík
2019-10-04 08:47:32 UTC
This number of searches is defined in lib/lwres/include/lwres/lwres.h #define LWRES_CONFMAXSEARCH 8 /*%< max 8 domains in "search" entry */ No support for dynamic unlimited list is present. Steps to Reproduce: 1. sed -i 's/^search .*/search non-existent1.very-long-domain.fedoraproject.org non-existent2.very-long-domain.fedoraproject.org non-existent3.very-long-domain.fedoraproject.org non-existent4.very-long-domain.fedoraproject.org non-existent5.very-long-domain.fedoraproject.org non-existent6.very-long-domain.fedoraproject.org openstacklocal redhat.com/' /etc/resolv.conf 2. [ "$(host access)" == "$(getent host access.redhat.com.)" ] && echo matches 3. sed -i 's/^search .*/search non-existent1.very-long-domain.fedoraproject.org non-existent2.very-long-domain.fedoraproject.org non-existent3.very-long-domain.fedoraproject.org non-existent4.very-long-domain.fedoraproject.org non-existent5.very-long-domain.fedoraproject.org non-existent6.very-long-domain.fedoraproject.org non-existent7.very-long-domain.fedoraproject.org non-existent8.very-long-domain.fedoraproject.org openstacklocal redhat.com/' /etc/resolv.conf 4. [ "$(host access)" == "$(getent host access.redhat.com.)" ] && echo still matches Not even the most recent development version handles this different way. Reported upstream [1]. 1. https://gitlab.isc.org/isc-projects/bind9/issues/1259 Patch submitted to upstream in https://gitlab.isc.org/isc-projects/bind9/merge_requests/2446 Development Management has reviewed and declined this request. You may appeal this decision by using your Red Hat support channels, who will make certain the issue receives the proper prioritization with product and development management. https://www.redhat.com/support/process/production/#howto |