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Troubleshoot name service issues

Contributors netapp-aherbin netapp-ahibbard netapp-thomi
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When clients experience access failures due to name service issues, you can use the vserver services name-service getxxbyyy command family to manually perform various name service lookups and examine the details and results of the lookup to help with troubleshooting.

About this task

  • For each command, you can specify the following:

    • Name of the node or storage virtual machine (SVM) to perform the lookup on.

      This enables you to test name service lookups for a specific node or SVM to narrow the search for a potential name service configuration issue.

    • Whether to show the source used for the lookup.

      This enables you to check whether the correct source was used.

  • ONTAP selects the service for performing the lookup based on the configured name service switch order.

  • These commands are available at the advanced privilege level.

Steps

  1. Perform one of the following actions:

To retrieve the…​

Use the command…​

IP address of a host name

vserver services name-service getxxbyyy getaddrinfo vserver services name-service getxxbyyy gethostbyname (IPv4 addresses only)

Members of a group by group ID

vserver services name-service getxxbyyy getgrbygid

Members of a group by group name

vserver services name-service getxxbyyy getgrbyname

List of groups a user belongs to

vserver services name-service getxxbyyy getgrlist

Host name of an IP address

vserver services name-service getxxbyyy getnameinfo vserver services name-service getxxbyyy gethostbyaddr (IPv4 addresses only)

User information by user name

vserver services name-service getxxbyyy getpwbyname You can test name resolution of RBAC users by specifying the -use-rbac parameter as true.

User information by user ID

vserver services name-service getxxbyyy getpwbyuid
You can test name resolution of RBAC users by specifying the -use-rbac parameter as true.

Netgroup membership of a client

vserver services name-service getxxbyyy netgrp

Netgroup membership of a client using netgroup-by-host search

vserver services name-service getxxbyyy netgrpbyhost

The following example shows a DNS lookup test for the SVM vs1 by attempting to obtain the IP address for the host acast1.eng.example.com:

cluster1::*> vserver services name-service getxxbyyy getaddrinfo -vserver vs1 -hostname acast1.eng.example.com -address-family all -show-source true
Source used for lookup: DNS
Host name: acast1.eng.example.com
Canonical Name: acast1.eng.example.com
IPv4: 10.72.8.29

The following example shows a NIS lookup test for the SVM vs1 by attempting to retrieve user information for a user with the UID 501768:

cluster1::*> vserver services name-service getxxbyyy getpwbyuid -vserver vs1 -userID 501768 -show-source true
Source used for lookup: NIS
pw_name: jsmith
pw_passwd: $1$y8rA4XX7$/DDOXAvc2PC/IsNFozfIN0
pw_uid: 501768
pw_gid: 501768
pw_gecos:
pw_dir: /home/jsmith
pw_shell: /bin/bash

The following example shows an LDAP lookup test for the SVM vs1 by attempting to retrieve user information for a user with the name ldap1:

cluster1::*> vserver services name-service getxxbyyy getpwbyname -vserver vs1 -username ldap1 -use-rbac false -show-source true
Source used for lookup: LDAP
pw_name: ldap1
pw_passwd: {crypt}JSPM6yc/ilIX6
pw_uid: 10001
pw_gid: 3333
pw_gecos: ldap1 user
pw_dir: /u/ldap1
pw_shell: /bin/csh

The following example shows a netgroup lookup test for the SVM vs1 by attempting to find out whether the client dnshost0 is a member of the netgroup lnetgroup136:

cluster1::*> vserver services name-service getxxbyyy netgrp -vserver vs1 -netgroup lnetgroup136 -client dnshost0 -show-source true
Source used for lookup: LDAP
dnshost0 is a member of lnetgroup136

  1. Analyze the results of the test you performed and take the necessary action.

    If the…​ Check the…​

    Host name or IP address lookup failed or yielded incorrect results

    DNS configuration

    Lookup queried an incorrect source

    Name service switch configuration

    User or group lookup failed or yielded incorrect results

    • Name service switch configuration

    • Source configuration (local files, NIS domain, LDAP client)

    • Network configuration (for example, LIFs and routes)

    Host name lookup failed or timed out, and the DNS server does not resolve DNS short names (for example, host1)

    DNS configuration for top-level domain (TLD) queries. You can disable TLD queries using the -is-tld-query-enabled false option to the vserver services name-service dns modify command.
Related information

NetApp Technical Report 4668: Name Services Best Practices Guide