3.6. Domain-to-Realm Mapping


When a client attempts to access a service running on a particular server, it knows the name of the service (host) and the name of the server (foo.example.com), but because more than one realm can be deployed on your network, it must guess at the name of the realm in which the service resides.
By default, the name of the realm is taken to be the DNS domain name of the server in all capital letters.
foo.example.org  EXAMPLE.ORG
foo.example.com  EXAMPLE.COM
foo.hq.example.com  HQ.EXAMPLE.COM
In some configurations, this will be sufficient, but in others, the realm name which is derived will be the name of a non-existent realm. In these cases, the mapping from the server's DNS domain name to the name of its realm must be specified in the domain_realm section of the client system's krb5.conf. For example:
[domain_realm]
.example.com = EXAMPLE.COM
example.com = EXAMPLE.COM
The configuration specifies two mappings. The first mapping specifies that any system in the example.com DNS domain belongs to the EXAMPLE.COM realm. The second specifies that a system with the exact name example.com is also in the realm. The distinction between a domain and a specific host is marked by the presence or lack of an initial period character. The mapping can also be stored directly in DNS.
Red Hat logoGithubRedditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

© 2024 Red Hat, Inc.