A machine may not always be on the same network as the IPA domain; for example, a machine may need to be logged into a VPN before it can access the IPA domain. If a user logs into a system when it is offline and then later attempts to connect to IPA services, then the user is blocked because there is no IPA Kerberos ticket for that user. IPA works around that limitation by using SSSD to store the Kerberos passwords in the SSSD cache.

This is configured by default by the ipa-client-install script. A configuration parameter is added to the /etc/sssd/sssd.conf file which specifically instructs SSSD to store those Kerberos passwords for the IPA domain:

[domain/example.com]
cache_credentials = True
ipa_domain = example.com
id_provider = ipa
auth_provider = ipa
access_provider = ipa
chpass_provider = ipa
ipa_server = _srv_, server.example.com
krb5_store_password_if_offline = true

This default behavior can be disabled during the client installation by using the --no-krb5-offline-passwords option.

This behavior can also be disabled by editing the /etc/sssd/sssd.conf file and removing the krb5_store_password_if_offline line or changing its value to false.

[domain/example.com]
...
krb5_store_password_if_offline = false