When the XOS CLI command configure dns server is used to assign a DNS server to be used by VAP groups on the system, the VAP group must be specified in the command.
Note: The XOS Command Reference Guide states that if the vap-group parameter is not specified when configuring DNS, the setting will apply to all VAP groups in the chassis. This is incorrect; leaving out the vap-group parameter assigns a DNS server that can be used by the CPM, but the DNS server is not assigned to VAP groups. This information will be corrected in future releases.
Failure to add the vap-group parameter to the configuration command line will result in DNS not working for the VAP group. If the specific VAP group is not named, the /etc/resolv.conf files are not updated on the APMs in the VAP group, resulting in the DNS lookups failing.
In order to configure a VAP group to use a specific DNS server, the VAP group has to be named within the CLI command. For example:
CBS# configure dns server 18.104.22.168 vap-group fw
You can verify that the DNS server has been added to the configuration by running the show dns-server CLI command, or by reviewing the /etc/resolv.conf file on each VAP group member.