Mastering Perl/Tk

IPADM Design Considerations

The programs detailed in the remainder of this chapter work in unison to help manage Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) configuration files. Now, you don’t have to know anything about DHCP or DNS, or managing IP networks for that matter; we’re more concerned with how to manipulate these files remotely, rather than with their actual content.

Suppose we have a company, ACME Rocket Supply, Incorporated, which has a class B IP network, 192.168.0.0.^[3] The site administrator has subnetted this address space by department; for instance, IP numbers 192.168.1.0 through 192.168.1.255 are assigned to the accounting department, while 192.168.2.0 through 192.168.2.255 are for purchasing. The administrator also decided to make each department responsible for managing its own computers and printers, and has delegated and trained several responsible persons. But he doesn’t want his helpers to have direct access to the server machine. So he has written a Perl/Tk TCP/IP client, ipadm, for remote IP administration.

There are various DHCP and DNS programs, and ACME.com’s network administrator chose not to limit his choices by writing ipadm for any particular flavors. Instead, he invented a metafile that describes an individual subnet, which can be sent to a filter to produce DHCP and DNS configuration files in whatever format is required. It’s these metafiles (subnet definitions) that are remotely manipulated. Each subnet definition ...