Proxy Servers & Firewalls

What is proxy ?

Main purpose of using proxies

How a proxy works ?

Proxy types

Popular hardware & software proxies

What is firewall ?

Main purpose of using firewalls

How a firewall works ?

Firewall types

Popular hardware & software firewalls

Objectives

What is proxy ? Proxy Proxy is hardware / software Indirect access to other networks e.g INTERNET. all computers on the local network have to go through it before accessing information on the Internet. Organization , universities , companies use proxy systems Proxy act as gateway Proxy act as Cache Server/Firewall Proxy share a connection to others LAN INTERNET

Main purpose of using proxies

Improve Performance

Act as Cache server

Bandwidth control

Filter Requests

Prevent access to some web sites!!!

Prevent access to some protocols

Time division

Surfing Anonymously

Browsing the WWW without any identification!!!

Improve Performance

Caching

Reduce latency

Reduce Network Traffic

Caching can greatly speed up Internet access. If one or more Internet sites are frequently requested, they are kept in the proxy's cache, so that when a user requests them, they are delivered directly from the proxy's cache instead of from the original Internet site.

Caches diminish the need for network bandwidth, typically by 35% or more, by reducing the traffic from browsers to content servers.

Bandwidth control

Policy-based Bandwidth Limits

Deny by content type

INTERNET 64 Kbps 128 Kbps 512 Kbps 1 Mbps

Filter Requests

Prevent access to some web sites!!!

Categories web sites

Adult/Sexually Explicit

Advertisements & Pop-Ups

Chat

Gambling

Games

Hacking

Peer-to-Peer

……

Check by content type

.Exe / .Com

.Mid / .MP3 / .Wav

.Avi / .Mpeg / .Rm

What do you need for proxy installation?

Proxy Software

Ms ISA Server , Squid , WinRoute , …

Server

At least 2 network cards

DIRECT INTERNET connection (Public IP Address)

Switch/Hub (elective)

Private IP Address

10.0.0.1/8 – 172.16.0.1/16 – 192.168.0.1/24

How a proxy works ?

See the next Demo

IP : 172.16.0.2 Gw : 172.16.0.1 IP : 172.16.0.1 IP : 217.219.66.2 Gw : 217.219.66.1 LAN INTERNET Proxy Server Source IP 172.16.0.2 www.yahoo.com Dest IP 209.191.93.52

IP : 172.16.0.2 Gw : 172.16.0.1 IP : 217.219.66.2 Gw : 217.219.66.1 IP : 172.16.0.1 Change Source IP Address LAN INTERNET Proxy Server Source IP 217.219.66.2 www.yahoo.com Dest IP 209.191.93.52 Source IP 172.16.0.2 www.yahoo.com Dest IP 209.191.93.52

IP : 217.219.66.2 Gw : 217.219.66.1 IP : 172.16.0.1 Change Source IP Address & Destination IP Address IP : 172.16.0.2 Gw : 172.16.0.1 LAN INTERNET Proxy Server Source IP 209.191.93.52 Dest IP 217.219.66.2

IP : 217.219.66.2 Gw : 217.219.66.1 IP : 172.16.0.1 Change Dest. IP Address IP : 172.16.0.2 Gw : 172.16.0.1 LAN INTERNET Proxy Server Source IP 209.191.93.52 Dest IP 217.219.66.2 Source IP 209.191.93.52 Dest IP 172.16.0.2

IP : 172.16.0.2 Gw : 172.16.0.1 IP : 217.219.66.2 Gw : 217.219.66.1 IP : 172.16.0.1 LAN INTERNET Proxy Server Source IP 209.191.93.52 Dest IP 172.16.0.2

Proxy types

Web proxies

SSL proxies

Transparent proxies

Open proxies

Anonymous proxies

Proxy setting in IE

Popular hardware & software proxies Software Proxy Hardware Proxy Ms. ISA Server Cisco PIX Squid Blue Coat Kerio WinRoute Cyberoam 1st Up Net Server Alacer CCProxy CProxy Windows ICS WinGate

What is firewall ? Firewall Firewall is hardware / software protects the resources of a private network from users from other networks Organization , universities , companies use firewall systems Firewall can act as gateway Firewall can act as proxy Firewall filter Incoming & Outgoing information LAN INTERNET

Main purpose of using firewalls

Packet filtering

Analyzing packets

Proxy service

Provide access to other networks e.g INTERNET

  LAN INTERNET

How a firewall works ?

The FIREWALL can now:

Log the attempt

Alert the admin

Harden the firewall

Or reset a TCP/IP connection

Sniffing Mode 1) An attacker tries to compromise a service on the protected network. 2) The Firewall identifies the attempt . LOG Alert  Reset Harden

What firewall protects us from

Remote login

Application backdoors

Operating system bugs

Denial of service

E-mail bombs

Viruses

SPAMs

Trojans

ICMP bombing

FTP brute force

Phishing

… .

Popular hardware & software firewalls Software Firewall Hardware Firewall Ms. ISA Server Cisco PIX Norton Internet Security Blue Coat Mcafee Internet Security Cyberoam ZoneAlarm Check Point Kerio NetScreen BlackICE D-link SECURESPOT Outpost WatchGuard