IP address conflict

I have a wireless network configured with 2 Wireless routers set up with
DHCP - non-conflicting ranges and 6 computers set up with fixed IP . I have
not set any encryption as I want casual users to be able to logon in our
cafe and use our Internet.
Recently I am getting an ip conflict popup on one of the pcs which I can
only imagine is caused by a neighbour's warless LAN . Is there anything I
can do about this ?



--
Posted via a free Usenet account from http://www.teranews.com

"-keevill-" <keevillus@yahoo.com> hath wroth:

>I have a wireless network configured with 2 Wireless routers set up with
>DHCP - non-conflicting ranges and 6 computers set up with fixed IP . I have
>not set any encryption as I want casual users to be able to logon in our
>cafe and use our Internet.
>Recently I am getting an ip conflict popup on one of the pcs which I can
>only imagine is caused by a neighbour's warless LAN . Is there anything I
>can do about this ?

If the two networks have different SSID's, then there won't be any
cross pollenation.

With no encryption, there's nothing to prevent someone from connecting
using their own invented static IP address. That's probably where
your IP address conflict is coming from. My guess(tm) is someone
sniffed the traffic, extracted your IP address layout, and decided to
"borrow" one of your client's IP addresses.

Do your static IP's land in the middle of either DHCP range? If so,
you may eventually have an address conflict. I know you said
"non-conflicting" but I can't tell exactly what is non-conflicting.
The 6 computers with fixed IP's or the DHCP ranges?


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

> If the two networks have different SSID's, then there won't be any
> cross pollenation.

They have different SSIDS , I can see the name of his network on our
machines when we scan network for wireless routers.



> With no encryption, there's nothing to prevent someone from connecting
> using their own invented static IP address. That's probably where
> your IP address conflict is coming from. My guess(tm) is someone
> sniffed the traffic, extracted your IP address layout, and decided to
> "borrow" one of your client's IP addresses.

Yes that's what I am guessing too. Is there anyway to prevent that ? Perhaps
block an ip range on our network ??

>
> Do your static IP's land in the middle of either DHCP range? If so,
> you may eventually have an address conflict. I know you said
> "non-conflicting" but I can't tell exactly what is non-conflicting.
> The 6 computers with fixed IP's or the DHCP ranges?
>
>
The wired machines have fixed ip in the range 192.168.0.1-10
The 1st router has DCHP range of 192.168.0.50-80
The 2nd router has DCHP range of 192.168.0.100-120

Thanks !!



> Jeff Liebermann jeffl@cruzio.com
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558



--
Posted via a free Usenet account from http://www.teranews.com

"-keevill-" <keevillus@yahoo.com> hath wroth:

>> If the two networks have different SSID's, then there won't be any
>> cross pollenation.
>
>They have different SSIDS , I can see the name of his network on our
>machines when we scan network for wireless routers.

Well, that mostly eliminates your neighbor as a possible culprit. His
wireless computah might have been setup to connect to literally ANY
wireless access point, which I guess would include yours. However,
that's not the default and rather uncommon.

>Yes that's what I am guessing too. Is there anyway to prevent that ? Perhaps
>block an ip range on our network ??

Nope. He'll just find another IP address to borrow.

I have a similar "open" setup. I use a MAC address filter for the
wireless connections. It's very easy to bypass, but it does serve the
purpose of preventing accidental connections. I have a neighbor that
just can't stay off the porno sites. He has his own wireless router
and DSL, but he turns it off a night. Meanwhile, the laptop wanders
over to my system and spews viruses and worms. So, I made a list of
the acceptable MAC addresses, applied the NAC filter, and he was
history. He could easily change his MAC address, but I have a trick
that will easily detect his laptop. The SSID is my address, so if
anyone wants to use the system, they can bang on the door or call me.
I've added about 10 such transient laptops for various neighbors.

>The wired machines have fixed ip in the range 192.168.0.1-10
>The 1st router has DCHP range of 192.168.0.50-80
>The 2nd router has DCHP range of 192.168.0.100-120

Perfect. The IP conflict is not coming from one of your machines.
Unfortunately, that probably means a hacker or someone looking for
some free bandwidth. Such is the joy of running an open and
unencrypted wireless system. Good luck.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558