Directory Servers

• Purposes (From Chapter 6)– Help users find information– Centralize security (single login, etc.)

Directory Servers• Information is Organized Hierarchically

– Hierarchy of objects– X.500 Standard defines types of objects– Also defines object properties

Organization (O) = xxx

Organizational Unit (OU) = yyy

Employee (E) = zzzCommon Name=Pat Lee

E-Mail=Lee…

Directory Servers

• LDAP– Lightweight Directory Access Protocol– Most popular directory access protocol– Governs user interaction with directory server

DirectoryServer

LDAP

Directory Servers• Directory Server Markup Language

(DSML)– Standardized way for application servers to

interact with directory servers– Application server may collect data from

multiple directory servers, present integrated results to browser user

DirectoryServerApplication

Server

DSML

Directory Server Products

• Directory Server Products– Novell Directory Services (NDS)

• From Novell

• Book incorrectly calls it NetWare Directory Services

• Mature, widely used

– Active Directory• From Microsoft

• New

Converging Boxes• Today, Many Types of Devices• Forwarding

– Hubs, Switches, Routers

• Security– Firewalls, etc.

• In future, single Comprehensive Relay Devices will combine forwarding and security

CRD

Converging Boxes

• Multi-Layer Packet Analysis

– Comprehensive relay devices will analyze headers and data fields at all layers

– For intelligent forwarding, like Layer 4 switches

– For intelligent security, like firewalls

– This will reduce costs compared to having separate devices

Converging Boxes

• Processing Concerns

– Multi-layer forwarding will be processing intensive

– So will be multi-layer security

– Processors must grow in power to keep up with increasing demand plus multi-layer processing and security

Policy Based Networking

• Policy Servers will Store Policies and Related Data– Will control individual forwarding, security,

and comprehensive relay devices– Uniformity in policy implementation

CRD

CRDPolicy

Policy

Policy Server

Policy Based Networking

• COPS– Common Open Policy Service– Standardized way for policy servers to talk with

devices for which they set policy

CRD

CRDCOPS

COPS

Policy Server