Unix Naming Services
Naming services means a repository that stores information that can be acquired by clients (users and applications) in a simple way. It allows the users to retrieve query or update information for the sake of enabling different computers to share authenticated and authorized information as a result of storing it in a central repository governed by a certain naming service.
Name services enables storing of data or information in a central place where the users, workstations, and applications such as: Machine (host) names and addresses, user names, passwords, and access permissions have to be communicate across a network. Solaris and systems in 2001 stated, “Without a central name service, each workstation would have to maintain its own copy of this information. ” Name service information may be stored in files, maps, or database tables. Centrally locating this data makes it easier to administer large networks.
Common functions of the name services are to associate (bund) names with objects, resolve names to objects, remove bindings, list names and rename. The examples of currently available Windows naming services include the flat files, Windows Internet Name Service (WINS), Domain Name System (DNS), LDAP-based naming services, and Windows Security database (SAM or AD). Like Windows UNIX OS also supports a wide range of naming services including flat files, DNS, LDAP, Network Information System (NIS) and the Network Information System Plus (NIS+).
(De Clercq, 2004) This paper will provide a brief but high level summary of some of these UNIX OS naming services with an overview towards comparing them and assessing details of each services’ operability. Finally it will discuss requirement especially future considerations and describe informative resources helpful to planning for a robust and secure naming infrastructure. Assessment of The Unix Naming Services revolves round specific service capabilities (mainly the name space, data storage types and server types) and most importantly the security.
Flat Files At first naming information was local to each system in flat files. Next a system for centrally storing and distributing these files was devised which was then improved with a hierarchical structure and provisions for authentication, authorization and transport security. Today the Information technology industry is standardizing on a general-purpose directory service that is based on open standards and is highly configurable, extensible and has provisions for authentication, authorization and transport security.
Flat file system of Unix OS had hostnames; usernames and essential environment information stored locally to each system in files within directories and could be assigned to an owner or group that was in charge. The access permissions could then be set for the owner, the group and others. It was problematic to keep this data updated and synchronized for deployments of more than a few machines. There was a manifest need for a mechanism to centrally manage this data within a network. According to De Clercq on Naming services in 2004, solutions to flat file were NIS and DNS Domain Naming Service (DNS)
DNS was developed to manage host names across various interconnected networks/ Internet. The development of DNS led to implementation of confidential files to allow the system administrator to determine the precedence and behavior of information lookups on a particular system. Currently administrators are able to specify all sources for information, search order and the behavior in the event of a failure. It was expressly intended to provide host name to address mapping across the Internet. Its naming space was hierarchical in nature: authority over different domains was delegated allowing for distributed management.
(O’Reilly & Associates, Inc. , 1999) It served only as a host name resolution service so there remained a need for a more general-purpose directory. Network Information System (NIS) The Network Information Service (NIS) was developed by Sun Microsystems to manage essential system information within a network. Network Information Service was introduced to manage much of the information represented in established flat files that ware mainly presented to the network as “maps” and could be accessed through various remote procedure calls.
These was possible because typically there can be multiple maps corresponding to each file hence multiple ways of accessing the information. NIS was fairly simple to implement. It had a flat file structure that was an easy transition for system administration, it was ubiquitous: and was based on the Open Network Computing (ONC) specification published by Sun Microsystems and due to its popularity, it became an attractive choice for managing heterogeneous systems.
By today’s standards NIS is considered to be quite insecure because of lacking a host authentication mechanism and encryption/decryption procedure. Its security model was based on a high degree of trust within the network environment this made security to be its biggest deficiency (De Clercq, 2004). Any client could connect to the server by simply broadcasting a bind request with the correct domain name in clear text and all subsequent requests for information would be granted including a request for the passwords and shadow maps.Sample Essay of AssignmentExpert.com