Proxy & Firewall
Download
Report
Transcript Proxy & Firewall
Proxy Servers
&
Firewalls
Objectives
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
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
Bandwidth control
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.
– Policy-based Bandwidth Limits
– Deny by content type
INTERNET
512 Kbps
128 Kbps
64 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
Switch/Hub (elective)
Private IP Address
(Public 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
Source IP
LAN
IP
: 172.16.0.2
172.16.0.2
www.yahoo.com
Dest IP
209.191.93.52
Gw : 172.16.0.1
IP : 172.16.0.1
Proxy Server
INTERNET
IP
: 217.219.66.2
Gw : 217.219.66.1
IP
LAN
: 172.16.0.2
Gw : 172.16.0.1
Source IP
172.16.0.2
www.yahoo.com
Dest IP
209.191.93.52
IP : 172.16.0.1
Source IP
Change Source IP Address
217.219.66.2
www.yahoo.com
Dest IP
209.191.93.52
Proxy Server
INTERNET
IP
: 217.219.66.2
Gw : 217.219.66.1
IP
LAN
: 172.16.0.2
Gw : 172.16.0.1
IP : 172.16.0.1
Proxy Server
IP
: 217.219.66.2
Gw : 217.219.66.1
Source IP
INTERNET
209.191.93.52
Dest IP
217.219.66.2
Change Source IP Address
& Destination IP Address
IP
LAN
: 172.16.0.2
Gw : 172.16.0.1
Source IP
209.191.93.52
Dest IP
172.16.0.2
Source IP
209.191.93.52
Change Dest. IP Address
Dest IP
217.219.66.2
IP : 172.16.0.1
Proxy Server
INTERNET
IP
: 217.219.66.2
Gw : 217.219.66.1
LAN
IP
: 172.16.0.2
Gw : 172.16.0.1
Source IP
209.191.93.52
Dest IP
172.16.0.2
IP : 172.16.0.1
Proxy Server
INTERNET
IP
: 217.219.66.2
Gw : 217.219.66.1
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
INTERNET
LAN
How a firewall works ?
Sniffing Mode
1) An attacker tries to compromise a service on the protected
network.
2) The Firewall identifies the attempt.
Reset
Harden
Alert
The FIREWALL can now:
LOG
• Log the attempt
• Alert the admin
• Harden the firewall
• Or reset a TCP/IP connection
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
References :
www.cisco.com
www.isaserver.org
www.wikipedia.com
www.cert.org
www.isc.sans.org
www.zonelabs.com
www.symantec.com
www.mshdiau.ac.ir
Communication & Information Technology Department of Mashhad
University - IRAN
Thank You,
Contact me : [email protected]
http://poustchi.blogspot.com