Firewall:
- Monitor internet traffic
- Restrict internet usages
- Proxy: cache webpage = save webpage
- VPN...
ISA Firewall => must 2 Network cards
1. WAN Network card: set ip ISP
2. LAN Network card: Set ip local network
- Firewall: software & hardwae
Firewall Software:
- ISA Server: Run on Windows 2003
- IPCop: Linux-base
- Smoothwall
- MicroTec...
Harware Firewall:
- Cisco ASA, PIX => Router
- Watchguard => Router
- LinkSys, Dlink => Router
ADSL Router:
- Router
- Modem
- Switch
- Wifi
------------------------------------------
Internet Traffic:
- Incoming traffic: Download
- Outgoing traffic : Upload
- Send email: outgoing traffic
- open yahoo.com: in + out
- download software: in
- upload website to hosting: out
- User on internet remote VPN to local Office: inoming
- user on internet open webmail of local mail server: incoming
------------------------------------------
- Network 4 category:
- localhost: local computer: 127.0.0.1
- Internal: LAN: local network
- External: WAN: Internet
- VPN: Extranet: local network stay on internet
Router:
- WAN: 203.189.128.222
- LAN: 10.0.0.1
2000-2003
- Modem: converter line to network sinal
- Router: NAT (map internal & external to same network)
- Switch: Share internet
2005: Router: 3-1