How come I can see other networks and does that mean they can see me?

[sarah_2677]

Hello,

I have a desktop pc with Virgin Media Broadband via a modem. My Dad's just got a laptop so I've bought a linksys router (Linksys Wireless-G DSL/Cable Router). I had problems installing via the CD so I had to ring the helpline and they talked me through it. They originally helped me set up a WEP code but I changed that to a WPA. I am concerned however as I have never had a laptop or used wireless before and when I click on connect to a network on the laptop I can see my own network but I can also see 3 or 4 others which I am guessing are neighbours networks. Therefore I am concerned that if I can see them can they see me and does that mean they can see what I am buying on the internet etc and my card details or if I am doing online banking? Thanks

[Graham M]

Your neighbours networks can be seen as can yours but as your network is connected via a WPA encryption key you are in theory safe

[DaiNasty]

If you are connected to a secured WPA password-protected router then your neighbours will be able to see that your network exists but will not be able to connect without the password.

From my house I can see 3 neighbouring networks but they are all secure. The WPA and password is the key.

[Rob]

You can stop your network identity being broadcast by turning SSID off on the router. But that makes it harder for you to connect any new devices yourself.

[Paul M]

Its a bit like knowing you neighbour has a postbox - you can see it but without the front door key you cannot get in to read their mail.

[Matth]

Nonbroadcast SSID was once a common suggestion to improve security, but even if the router is not actively broadcasting, the SSID will still leak from the PC hunting when it is not available, and from traffic when it is.

At best, nonbroadcast SSID prevents accidental connection, but then so does proper security. At worst, not broadcasting denies a useful channel management tool, as when setting up other networks, you, or an autoselecting router, may choose to avoid nearby occupied channels if possible.

NB. Since the channels spread, usable UK channel plans are:
1, 6/7, 11 (pretty much the default if 1-11 US spec is used) - 1, 4, 7, 11 is a compromise with some channel splash.
1, 5, 9, 13 (optimum 1-13 usage, though 9 can be badly hit by microwaves).


Security:
WEP is cracked, 64 bit WEP is badly cracked, 128 bit cracked, while 256 bit (nonstandard) is probably reasonably safe.

WPA is preferred, a much better system so far more resistant than WEP

Another measure that can be applied is MAC address filtering, but anyone capable of breaking the actual security layer could also spoof a MAC address, so like nonbroadcast SSID, this acheives very little on top of WEP or WAP, except that MAC filtering is a useful gatekeeper in case you wish to deny access to a particular user (maybe a one time guest) without changing the key on all other systems, though this is something you should be prepared to do.