Wireless security

ajm · 26 Aug 2006 at 08:00

I have read a few parts of the sticky's but don't seem to understand it all.I have 3 pcs 1 wired and 2 wireless using Linksys WRT54G router.I am wanting to make sure that only the 3 pcs in my house can connect using certain ip addresses.I have tried changing Maximum Number of DHCP Users: to 3 but with the pc's not been on all the time someone else seems to be taking one of the ip addresses.Please can someone help me with simple instructions as this is quite new to me? :confused:

BenST · 26 Aug 2006 at 09:12

You have two options. The first and simplest option would be to assign each PC their own static IP. The second option is to upgrade your router with dd-wrt firmware and activate the static DHCP server option which assigns PCs with user defined IP addresses based on their MAC address.

I use the latter option as it's handy to have the laptop set to DHCP when I'm out and about and it's good to have the same IP assigned to my laptop for when I use port forwarding etc

Flying_V · 26 Aug 2006 at 09:33

I would just use static addresses as once you set the 3 up you're done. You just need to turn the DHCP server off on the router (there should be a tick box for this). Then assign static IP addresses to your 3 machines by going into the network connection of each and changing it from 'obtain an address automatically'.

If your router has address 192.168.1.1 you need to give your PC's addresses in that range - 192.168.1.2, 192.168.1.3 and so on. Then make sure you have your wireless security set up and no other machines should be able to get on your network.

ajm · 26 Aug 2006 at 16:50

Thanks for the info i will take a look into this,it still sounds a bit confusing to me but i will try.

The Deuce · 26 Aug 2006 at 18:17

you could also turn your security on

and also allow the router to only allow the MAC codes relevant to your network

tolien · 26 Aug 2006 at 20:18

The Deuce said:
you could also turn your security on and also allow the router to only allow the MAC codes relevant to your network

Assuming the clients are connecting over the wireless network. Encryption and/or a MAC address access list only applies to the wireless.

The Deuce · 26 Aug 2006 at 20:31

ajm said:
I have 3 pcs 1 wired and 2 wireless using Linksys WRT54G router.

tolien · 26 Aug 2006 at 20:33

with the pc's not been on all the time someone else seems to be taking one of the ip addresses.

No mention of the machine taking the IPs being wireless, nor being uninvited.

Escape · 27 Aug 2006 at 01:15

Flying_V said:
If your router has address 192.168.1.1 you need to give your PC's addresses in that range - 192.168.1.2, 192.168.1.3 and so on.

Are there any security benefits in assigning random IP addresses on a wireless network, e.g. 192.168.1.55, 192.168.90.142 etc?

tolien · 27 Aug 2006 at 01:25

Given you can ping the broadcast IP and watch them all respond (assuming there isn't a firewall blocking ICMP Echo Requests/Replies for the LAN IPs), not really.

As long as you know the first three octets, you can keep trying till you hit on an IP that works. At least if the IPs are in a contiguous block it makes explicit blocking easier.

ajm · 27 Aug 2006 at 10:46

No mention of the machine taking the IPs being wireless, nor being uninvited.

The machine is uninvited and must be wireless.

All this talk about mac addresess,static IP addresses and DHCP servers is new to me and i don't know what to do.Can anyone give me a simple step by step guide.Also if i assign static ip's will it stop this unknown machine taking an ip when the other pc's aren't on?

tolien · 27 Aug 2006 at 11:38

ajm said:
Also if i assign static ip's will it stop this unknown machine taking an ip when the other pc's aren't on?

You'd need to disable the DHCP server too.

As for security, as much instruction as you need should be contained in the manual for your router and the wireless sticky. There's not much point setting allowed MAC addresses, but it is worthwhile switching on encryption (and use WPA in preference to WEP).