Proxy Server 2.0 Microsoft Proxy Server 2.0. Presentation Outline Overview of Proxy Server. Examples...
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Transcript of Proxy Server 2.0 Microsoft Proxy Server 2.0. Presentation Outline Overview of Proxy Server. Examples...
Presentation Outline
Overview of Proxy Server.
Examples of Capacity Planning.
Web Proxy Server Configuration.
Proxy Server Auto Dial.
Overview of Proxy Server
What is Proxy Server ?
Firewall Server.
Web Cache Server.
3 Proxy Services – Web Proxy, WinSock Proxy, and SOCKS Proxy.
System Requirements.
What is Proxy Server ?
A secure gateway between a protected network (LAN) and the Internet.
Mediates traffic and processes all incoming and outgoing requests.
Application server that acts as both a firewall server and a web cache server.
Only One IP address is “visible” to outside world.
Proxy Server ExampleProxy Server Example
LANInternet
FTPGopherHTTP
Win NT
IIS
Proxy
Traffic
LAN
One IP address is visible.
IP addresses are hidden.
What is a Firewall ?What is a Firewall ?System that enforces an access control policy between two networks.Some block traffic; others permit traffic.Protects against unauthenticated logins from the “outside.”A “phone tap” and tracing tool.Cannot protect against attacks outside of the firewall and viruses.
Types of FirewallsTypes of Firewalls
Network Level (Router).Decisions based on source, destination
addresses and ports in IP packets.Route traffic directly, fast and transparent.
Application Level (Proxy Server)Permit no direct traffic between networks.Good for logging and access control.Provide detailed audit report.Enforce more conservative security.
Proxy Server as Firewall Proxy Server as Firewall ServerServer
Packet Filtering – examines all TCP/IP based attempts in & out of the network. Static and Dynamic.
Logs all connection attempts & alerts in real-time of the suspicious activities.Reverse Proxy - Places the web server behind Proxy Server to publish to the Web. “Impersonates" a Web server to the outside. Reverse Hosting & Server Proxying.
Reverse Proxy ExampleReverse Proxy Example
Proxy
Web Server
InternetClientMkt Dept
LAN
Secure Network
www.company.com
www.company.com
www.company.com
MS Proxy Server as Web MS Proxy Server as Web Cache ServerCache Server
Web Caching – process of storing Web content locally to reduce network traffic.Active and Passive.
Allow internal clients to have full Web access behind the firewall without compromising security. Hierarchical Caching.Distributed Caching.
Cache ExampleCache Example
Internet
1st client 2nd client
Connection to Internet
ProxyContentCached
50% Traffic Saving
Cache Hit!
Hierarchical Caching Hierarchical Caching ExampleExample
InternetProxy
ProxyProxy
New York
Los AngelesBoston
Client Client Client Client
Distributed Caching Distributed Caching ExampleExample
Internet Proxy
1 Proxy
3 Proxy
4Proxy
2
Load BalancingFault toleranceScalability
Client Client Client Client Client Client
WinSock, SOCKS, Web WinSock, SOCKS, Web ProxyProxy
Protocols allow the application clients to communicate to application servers.
Performs three functions: Intercepts connection requests.Sets up proxy circuit.Relays application data.
WinSock & SOCKS Proxy
WinSock Proxy. For Window application. Creating virtual connection between Internal and
Internet application. Acts as gateway protocol for IPX/SPX.
SOCKS Proxy. Allows Unix, Mac and Window client application
that support SOCKS protocol specification. Handles all TCP/IP traffic through the proxy
server. Cannot Handle UDP based protocols.
Web ProxyWeb Proxy
Web ProxySupports any CERN web browser.Supports HTTP, FTP, SSL and Gopher
protocol.Enables its caching capabilities.
System RequirementsSystem Requirements
WinNT Server 4.0 with service pack 3 or later.
IIS – Internet Information Server.
Network interface card.
CPU and disk space: Intel based: 486/33MHz or higher & 125MB. RISC based: RISC processor compatible with
WinNT 4.0 & 160MB.
16MB of RAM.
Examples of Capacity Examples of Capacity PlanningPlanning
Small Office Network.
Medium-Size Office Network with a Branch Office.
Large Enterprise Network.
Example of Small Office Example of Small Office NetworkNetwork
Modem or ISDN line
ISP
Proxy Server(Win NT RAS client)
Web Server Mail Server
Internet
Client Client Client
ContentCached
LAN
Small Office NetworkSmall Office Network
Characteristic: A single LAN segment. Use of the IP network protocol. Demand-dial connectivity to an ISP. Fewer than 300 clients.
The proxy-based computers set up: One NIC to the internal network. One modem to the external network (Internet).
Uses Auto Dial for demand-dialing to Internet.
Caching is enabled and configured to limit the demand-dialing to the Internet.
Small Office Network Small Office Network Cont . . . Cont . . .
Stores a local copy of popular URLs in dedicated disk drive.
Uses a single network security policy. Password authentication. User permissions. Protocol definitions. Domain, cache and packet filtering.
Example of Branch Office Example of Branch Office NetworkNetwork
Internet
ISP
ProxyServerArrayWeb Server Mail Server
Router
Web Server
(Department LAN)
Modem or ISDN Line
Web Server
Remote Branch Office
Proxy server(Win NT RAS client)
Router on T1 line
Clients
LAN
Clients
Branch Office NetworkBranch Office NetworkCharacteristic . . . A central office with several LAN segments. A branch office with a single LAN segment. Use of the IP network protocol. Demand-dial connectivity from the branch office to the
central office. Dedicated-link connectivity from the central office to an
ISP. Fewer than 2,000 clients.
Auto Dial feature provides demand-dialing from remote office to central office.
Branch Office Network Cont . . .
Proxy-based computer set up at branch: One NIC to the local network (branch). One modem to remote network at the central office.
Caching is enabled to minimize demand-dialing to central office and to reduce long-distance phone charge.
Active caching should not be used at remote branch.
Branch Office NetworkBranch Office NetworkCont . . .Cont . . .
Global Security policy: Administrated at central office. Central office can also set and override local policy.
Remote branch proxy has no direct Internet access.
All clients requests are routed upstream to the proxy array at central office.
Example of Large Enterprise Example of Large Enterprise NetworkNetwork
InternetProxy ServerArray
Proxy ServerArray
RouterWeb Server
Department LAN
Web ServerMail Server
RouterWeb Server
Department LAN
ISP
CorporateNetwork
ClientsClients
Router on T1 line
Router
LAN
Large Enterprise NetworkCharacteristic . . . A central corporate office with many LAN
segments and a backbone LAN. Several branch offices, each with a single LAN
segment Use of both IP and IPX network protocols. Demand-dial connectivity from the branch office to
the central office. An ISP & Dedicated-link connectivity from the
central office to an ISP. More than 2,000 clients.
Large Enterprise Network Large Enterprise Network Cont . . .Cont . . .
Proxy array is used for: Distributed caching. Load balancing. Fault tolerance.
Proxy array handles all client Internet requests (locally or branch).Active caching to retrieve popular URLs.
Large Enterprise Network Large Enterprise Network Cont . . .Cont . . .
Uses single array member to administration all other proxy.Proxy array is used on the backbone LAN.Is used at ISP to demonstrate scalability.Local branch clients use Auto Dial for demand-dialing to RAS server.Internet requests not serviced locally are forwarded to corporate proxy array.Server administration is set and enforced at the central office.
Large Enterprise Network Large Enterprise Network Cont . . .Cont . . .
Departmental proxy connection: One NIC to departmental LAN. One NIC to backbone LAN.
Proxy array at backbone is dual-homed. Internal NIC. External NIC to Internet.
Proxy array at ISP: Massive scalability, load-balancing, and fault-tolerance. Can cache massive amount of information. Increases client performance. Preserves ISP’s bandwidth out to the Internet
backbone.
Proxy server configurationProxy server configuration
Uses Internet Service Manager.
General Proxy. Service page. Logging page.
Service Specific Proxy. Permission page. Caching page. Routing page. Publishing page.
Service Page Notes
Product release and ID.Current sessions – current user info.Shared service:Security – packet, domain filtering, alerting
and logging.Array, Auto Dial, and Plug & play.
Configuration:Client configuration, LAT, server backup
and restore.
Logging Page Notes
Sets logging options for web proxy, WinSock proxy, and SOCKS proxy.
Provides auditing trail.
Records client, server, connection, and object information.
Can log to text file or SQL/ODBC database.Database file requires more resources.
Permissions Page NotesPermissions Page Notes
Grant or deny access to services.
Can provide unlimited access to an individual user group.
Permission based on protocol via protocol definition.For example:
FTP.FTP Read.
Caching Page NotesCaching Page Notes
Sets location and size of the disk cache.
Enable or disable caching.
Can specify how often to update cache.
Increase cache size does not effect the data already cached.
Delete all cached content by setting cache size to zero.
Routing Page NotesRouting Page Notes
Information on directing client requests for Internet objects.
Direct connection or use proxy.
Can enable backup route.
Can enable routing within proxy array before routing upstream.
Can also configure web proxy clients.
Publishing Page Notes
Configures publishing requests.Configures Reverse proxy and hosting.Incoming requests:Discard.Sent to local web server.Sent to another web server.
Set default web server host by Default Mapping.
What is AutoDial?What is AutoDial?
Proxy server automatically dial out to an ISP for Internet connection.Uses Windows NT Server Remote Access Service (RAS) and Dial up Networking to establish a connection to an ISP.Event-driven Client requests can activate Auto Dial from the
WinSock and SOCKS Proxy Service. Web Proxy Service is activated when an object
requested is not located in the cache.
Auto Dial BenefitsAuto Dial Benefits
Can save company Internet charges Event-Driven - activated only when Internet
connection is needed. Regulate Usage - configured to connect to the Internet
during office hours only.
Can be used as backup to an existing continuous Internet links. only cost of configuring Auto Dial as continuous
Internet connection are the hardware & the online time when a continuous Internet link is down.
Steps to Configuring Auto Steps to Configuring Auto DialDial
Install Window NT Server Remote Access Service (RAS) and Dial-up Network before implementing Proxy Server Auto Dial. For security reasons, install RAS Server on
separate computer of the Proxy Server computer.
RAS and Dial-up Networking can be installed after or before the installation of Window NT Server 4.0.
Remote Access Service
Remote Access Service can be configured in Auto Dial as an:RAS Client - to dial out only.RAS Server - can be both dial out and
receive calls or just receive calls only.RAS Server requires a high level of
security on you Intranet.
Dial-up NetworkingDial-up Networking
Used to connect client to remote networks.
A phonebook entry stores all the setting needed to connect to a particular remote network. Personal phonebook. Company phonebook (public use).
Phonebook Entry IncludesPhonebook Entry Includes
Name of phonebook entry.
Connection method.
Phone number.
Serial line protocol offered by the server you are calling.
Whether or not to include a login script
IP address.
IP address of a DNS or WIN Server on the remote network or both.
FeaturesFeatures
Caching on command.
Client IP address forwarding.
Automatic content discoveryDynamic proxy routing.
Enterprise Management.
Fine Grained Filtering.
Administrative Control.
Caching on CommandCaching on Command
Automatically update and caches frequently accessed documents.
Documents or entire sites can be preloaded into the cache, and administrators can schedule updates of cached content.
Client IP Address Client IP Address ForwardingForwarding
Sends clients IP address to remote server if the Proxy is one of a chain of internal proxies.
Enterprise Management
Centralize Management. Support LDAP.Uses Directory Server to manage users
and password centrally.
Clustered Management.
Manual Configuration Files.
Custom log formats.
Fine Grained FilteringFine Grained Filtering
Access controls for sites, documents, and protocols.
Content filtering - built-in virus scanning.
Cross - platform generic protocol support.
Administrative ControlAdministrative Control
Ensures that users access network resources safely and productively.
Can specify distinct access controls based on access type.
Allows administrators to create custom HTML files to be returned to users when access is denied.
Netscape Proxy Server Netscape Proxy Server ImplementationImplementation
Bottleneck locations for implementing Proxy Server. Internet Gateway—Forward Proxy.Branch Office—Forward Proxy. Internet Gateway—Reverse Proxy.
Internet Gateway - Forward Proxy
Provides gateway services at the application level with a web proxy as well as at the circuit level through SOCKS. Enhances Internet access. Web content caching reduces response times.Facilitates bandwidth conservation.Helps reduce overall communications expense.Content filtering and access control allows easy management of intranet material.
Branch Office—Forward Proxy
Multiple proxy server allows chaining proxies together to create a hierarchical caching system
Proxy chaining allows multiple Netscape Proxy Servers to cache content locally setting up a hierarchy of servers for client access.
Internet Gateway—Reverse Proxy
Proxy Server is placed outside firewall to represent a content server to external clients.
Expose selected content without exposing web servers that host it or other elements of private network.
Multiple reverse proxy servers can be used to balance the load on an over-taxed web server.
Architecture
Dual-Homed Host Architecture
Screened HostScreened
Subnetwork
Reverse ProxyServer Stand-inLoad Balancing
Dual-Homed Host Architecture
Has two network interfaces, one connected to an internal LAN and the other to the Internet.
Incorporates a firewall software package.
Provides caching, fine-grain filtering and virus scanning.
Screened Host
Consists of a router deployed in front of a server that is hosted on a private network.
Router can be traditional hardware router or firewall software application providing packet-filtering capabilities and restricting inbound access to internal network.
Appropriate for small to medium-sized intranets that require a simple, yet effective security solution.
Proxy Server Implemented Behind a Screening Firewall
Internet
Firewall Software Router
Proxy Server
LAN
Client
Client
Screened Sub-network
Consists of multiple routers sandwiching a non-secure network that is outside or part of the firewall solution. Commonly referred to as a DMZ (demilitarized zone). Proxy is deployed in DMZ and is allowed access to both internal and external networks through routers. Popular architecture choice for larger organizations with heavily trafficked gateways.
Proxy Server in Reverse Mode as a Stand-in for a Web Server
Client
Internet
Firewall Enterprise Server
Proxy Server
Multiple Proxy Server in Reverse Mode to Balance the Load on a Web
Server
Internet
FirewallEnterprise ServerReverse
Proxies
DNS Server
Possible enterprise implementation
Internet Router
Central Office
Subnet
Proxy Server
Router
LAN
Client
Client
Router Router Proxy Server
LAN
Client
Client
BRANCH OFFICE
Bottlenecks
Chained Proxy Servers Providing Load Balancing and Fail-Over
Capabilities
Internet
Proxies
LAN
Router Router
LAN
Client
Client
Client
Client
Proxy A
Proxy 1
Proxy 2
Proxy 3
ConfigurationConfiguration
Automatic Client Configuration.
Caching.
Templates.
Filtering.
Server Plug-in Functions.
Automatic Client Configuration
Enables automatic proxy configuration in Navigator clients on intranet.Administered by a Proxy Automatic Configuration (PAC) file. PAC allows load balancing across multiple proxy servers and alteration of proxy architecture without modifying end user settings.
Caching
Caches should be approximately 1 GB per partition and spread across multiple disk controllers.
Refer to Administrator’s Guide for in-depth instructions on creating batch update configurations.
TemplatesTemplates
An object created in Proxy Server’s object configuration file, obj.conf.Used to assign unique procedures to specific URLs.Can make the server behave differently depending on the URL the client tries to retrieve.Allows customization of how Proxy Server interacts with clients.
Server Plug-in FunctionsServer Plug-in FunctionsExtends capabilities of proxy by using Netscape Server Plug-in Application Programming Interface, NSAPI.
Set of functions and header files use to create functions in the server configuration files. AuthTrans, PathCheck, NameTrans,DNS, Connect,
Addlog.
Use to create functions that uses a custom database for access control or create custom log files with special entries.
Maintenance/UpgradeMaintenance/Upgrade
MaintenanceTuning the ServersMonitoring the Servers
UpgradeGrowth IssuesLicensesSoftware Updates
Tuning Servers
Time-outs.Up-To-Date Checks.DNS Lookups:Enable DNS Caching.Log Only Client IP Addresses.Disable Reverse DNS.Avoid ACLs with Client Host Names.
HTTP Keep-Alive.
Monitoring ServersMonitoring Servers
Analyzing Logs.
Monitoring Performance:Cache Utilization.CPU Utilization.Memory Utilization.
Upgrade
Growth Issues Is proxy services strategic for business?Network bandwidth saturated?CPU utilization too high?Has a new field office been opened or a
department addedHas access content type been changed?
Upgrade (cont)
LicensesProxy User Licenses Proxy Servers
Purchased Deployed
1000 1
2000 2
3000 3
4000 4
Upgrade (cont)
Software UpdatesRefer to the Netscape Software Download
Site.Netscape Proxy Server provides on-the-fly
virus scanning of all incoming data, using the Trend Micro’s InterScan VirusWall Purchase of Proxy Server give you 90 days of free virus pattern updates.