Search Paths
Your network administrator or Internet Service Provider should
be able to give you the IP address of at least two domain name
servers that you can use (you can use only one, but its preferable
to have two, in case one becomes unreachable). These IP addresses
are entered in the TCP/IP control panel, in a list, with the most
reliable/closest dns servers first.
When you try to resolve a name, a query will be submitted to the
server at the top of the list first, and then it will work down
from there (for example, if the top server is unreachable). But
before a query can be submitted to the DNS server, it must be
a "fully-qualified" domain name, which means it must contain both
the name of the host, and the name of the host's domain.
For example, "jasper.austin.apple.com" is a fully-qualified domain
name, referring to a host (or machine) named "jasper", which lives
in the "austin.apple.com" domain ("austin" is a subdomain of the
larger "apple.com" domain). But nothing will stop you from trying
to open a connection using only "jasper". If you do so, an attempt
will be made to complete the name by appending a domain name to
it. You can enter in the TCP/IP control panel the names of search
domains, which will be appended to "jasper", or any other unqualified
domain name.
With these settings, when you try to connect to "Jasper", names
will be submitted for resolution in the following order, until
the name is resolved:
- jasper.esa.austin.apple.com (the starting domain)
- jasper.austin.apple.com (dropping one subdomain).
- jasper.apple.com (dropping another subdomain, till "ending" domain
name is reached).
- jasper.texas.net (the "additional" search name).
Each name is submitted to each of the name servers listed, in
order, until the name is resolved, or until the possibilities
have been exhausted. |