Transcript SOHO Wireless Networking

SOHO Wireless Networking
SCATA Nov 2005
Dr Duncan Hancox
Summary
• Intro to wireless networks
– Types of wireless
– Types of networking
– Basic wireless infrastructure
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Setting up
Extending the network
Extras
Security
Types of Wireless
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802.11b – 11mbits/sec
802.11g – 54mb/sec
802.11g turbo / super g – 108 or 125
802.11a – 5ghz – not compatible
802.11n – not standard (pre-n) but
backward compatible with b/g
Types of Wireless Networking
• Peer to Peer – not considered here but
has its uses to connect 2 machines
• Infrastructure – uses 1 or more wireless
access points (WAP)
Basic Infrastructure
To Internet
ADSL
Modem
Router
Firewall
Wired ethernet
WAP
DHCP
server
Switch
WAP
WAP
Single wired ethernet
Broadband Router
Switch
Intranet ethernet
To PCs
Router
Firewall
Ethernet to internet / network
Via broadband modem or
Cable or satellite
ADSL router modem switch
To Internet
Wired ethernet
ADSL
Modem
Router
Firewall
WAP
DHCP
server
Typical single box solution for home
Switch
Setting Up 1
WAP
Single wired ethernet
-Wireless card picks up the SSID automatically
Or is configured manually
-The WAPs DHCP server gives an IP
Or is configured manually
-Log into the WAP and change settings to suit
Setting Up 2
WAP
wired ethernet
Compters needs to be same ip address range as WAP – boot the computer
After connecting and plugging in to WAP if the WAP has a DHCP server
Enabled
Manually change the PCs wired etherenet IP address to suit the WAP
Windows assigns a random IP address to ethernet when not connected and
You will not see the WAP with this address!
Extending the Range 1
• High power hardware
• High gain antennas
– Omnidirectional 5-7db
– Directional 7-12db but expensive
WAP
Antenna and connector
may be unique to your
WAP
Extending the Range 2
• Additional WAPs wired together
WAP
WAP
Ethernet link
Use the same SSID on both allows seamless roaming
Use different radio channels for each WAP
Use same security settings
Extending the Range 3
• Wireless repeater / relay
ADSL
Router
WAP
Only works with the same manufacturer!
And only with some models
Repeater
Network Extras
• Print Servers
– Wired or wireless
– Slow
– Poor printer feedback eg ink level
• Hard drives / NAS
– Slow
Wireless Security 1
• SSID – name of the wireless network
– Nothing to do with the workgroup name
– If you turn of SSID broadcast, windows zero
configuration utility will fail
• WEP – weak
• WPA – slightly better
• MAC control
– much better but can be spoofed
– Stops guests easily connecting
Wireless Security 2
• Change the SSID name to something
cryptic and turn off SSID broadcasting
• Disallow admin options from the
broadband side of the router
• Change the router login from default
• Use WEP or WPA to discourages casual
browsers
• MAC control – best option to limit access