IP addresses & home networking advice

[mip1225]

Hi all,

was wondering if anyone knew how to get a list of all devices connected to my home network so i know what IP addresses are being used.

also i inputted a fixed IP address for my laptop but if i do a system restart it resets as if i never entered the fixed IP is thereany reason for this?

many thanks

[gman1981]

Firstly, your router should have a page which lists any devices connected to the network. What router do you have?

Secondly, what OS does your laptop have? If Windows, that behaviour seems odd.

[mip1225]

Hi there,

Its a Linksys router and modem..... ... will check it out... just wanna see if my neighbour is tapping into it!!!

and its Windows XP and yes i appreciate that it does sound strange but its happening i can assure to my frustration....

[gman1981]

Hmm, when you change to a static IP address, do you put in all the info.. IP, subnet, gateway, dns?

I think most Linksys routers will have a page on the web administration page which should show what is connected. If you know the model number I'll see if I can dig out the instructions.

[mip1225]

thanks

ip subnet dns etc.... yes, yes, yes and yes... saved then ok... when i do this it does reset to this as i do ipconfig straight after and it is the ip i set it to... but if i restart it reverts back to first available.


Linksys...its an old one ... WRT54GS i think.... i did have a quick look but did not see it anywhere when i logged in,... but it was a very quick look...

thanks for your help

[gman1981]

If I remeber right, there is a link on the Wireless section for editing allowed MAC addresses. That opens a new window which gives you a link to wireless connected devices. Or on the Status page there is a DHCP Client button which should give you a list too.

Can you screenshot the ip config page on your laptop and post it?

[mip1225]

theres a DHCP RELEASE and DHCP RENEW buttons on the bottom of the status page

cant post image???? not hosting .... cant just copy and paste!!!! lol

[gman1981]

http://downloads.linksysbycisco.com/...20070529,0.pdf
Use the above link and go to page 20. The right hand section is where you need to go.

Or page 11 for the Wireless MAC list.

[mip1225]

Hi there,

sorry for the delay... have looked around abit more so have questions... have found theDHCP clients table so know whats connected....

why does it only display 2 devices when i know there are 3 connected and turned on... 2 x laptops and Xbox 360.

a linksys guy suggested using the wireless mac filter... does this mean i have to input each mac address to allow it access....

is each mac address unique to the product (i.e. will it reset itself on restart)

does this mean that if i do enable thisprocess only items on this list will be allowed access?

sorry bet you wished you never got into this now!!! ooops my bad i am stupid!!

[gman1981]

The DHCP will only list devices connected via DHCP, which means the laptop which is statically assigned an IP won't appear on the list. If you are concerned about people piggy backing your wireless a MAC filter is a good, start, and easy to set up. You are right the MAC address is unique to the device, and never changes. However MAC filtering is not secure, anyone can easily spoof a MAC address and therfore get on to your wireless. Your best bet is to use WEP or prefrably WPA or WPA2 sercurity for your wireless.

[mip1225]

funny thing is that both laptops appeared and it was the xbox the wasnt there....

do you know how i obtain the mac address of each device??

also i currently use WEP but have been told WPA is better...??
can i just switch over to WPA....(i suppose what i mean is do all my devices have the facility to enable WPA security) not sure if am getting across what i mean!!

thanks

[gman1981]

Maybe the xbox hasn't been on for a while so the dhcp lease expired? The MAC address is usually stuck to the device or if windows type ipconfig /all at a command prompt to get the mac address. WPA is much better. You can just switch it over as long as all devices support WPA.

[mip1225]

it was on when i refreshed the dhcp table etc (trust me the 360 is on way too much for my liking no chance of it expiring!!)... which is weird.... anyway its answered the question of the device having to support the WPA security option first.

thanks!

[3xH]

also i currently use WEP but have been told WPA is better...??

With WEP someone can hack into your network in less than 5 mins if they want, with WPA they can not (As long as you use a complex key) so personally I'd say better was an understatement.

Using the MAC address filter will NOT protect your network as the MAC address is easily faked, nor will hiding the SSID (Network name) as this is also easily scanned. WPA or WPA2 is an ESSENTIAL minimum for any wireless network imo.

[peterb]

Wep is less secure than WPA - however to say "someone can hack it in
less than 5 minutes" is a gross overstatement.

Someone with the right equipment, time, knowledge and motivation could
hack into the network - but probably take longer than 5 minutes.

Are at risk of being targeted? If so WEP is not for you - otherwise it
is probably OK. I have used WEP for over 5 years without any problems.

That said, if you have WPA, available, and all devices support it, then
you might as well use it!

You should also use tie the MAC address to an IP address, and idealy not use DHCP either (on the wireless side - which may also preclude t onthe wired side as well (depending on the router)

[3xH]

Wep is less secure than WPA - however to say "someone can hack it in
less than 5 minutes" is a gross overstatement.

Someone with the right equipment, time, knowledge and motivation could
hack into the network - but probably take longer than 5 minutes.

Are at risk of being targeted? If so WEP is not for you - otherwise it
is probably OK. I have used WEP for over 5 years without any problems.

That said, if you have WPA, available, and all devices support it, then
you might as well use it!

You should also use tie the MAC address to an IP address, and idealy not use DHCP either (on the wireless side - which may also preclude t onthe wired side as well (depending on the router)

When I say 5 minutes, I'm talking from personal experience of breaking a WEP key on a WEP protected O2 (Thompson) ADSL router. All you need is a Laptop with a Wireless card, a certain Linux Live CD and Google. Granted under 5 mins is someone that has done it before. But 5 mins none the less. Certainly long enough to log is as the Admin user with detail obtained again from google, and change all the settings on the router in question to disrupt someones internet connection.

WPA can be cracked as well, but it takes significantly longer and requires that the key used is a word in a dictionary file. If the Key is a random assortment of upper and lowercase letters numbers and symbols this can be extended to a lifetime.

Both technology's also appear to be quite vulnerable to DOS attacks where you spam disconnect packets at a target device cloning the MAC address of the Wireless access point.

IMO the question of WEP is not whether you fell you may be targeted, but using WEP makes you a target. While it stops your non-technical neighbours stealing your broadband, its an invitation for any beadroom bound teenage geeks to mess with your network.