How To Secure A Wireless Network

[Fidgits]

well - if the information you posted is factually correct... then yes, i was wr... wr... wro.... I obviously mis-understood just how badly WEP was put together :P

[sotal]

you almost made it then, just two more letters and you would have been there

[Fidgits]

LOL...

Strangley, WEP is the one protocol i dont actually deal with normally, but I expected it to be the same as normal, but obviously i was wrong... but the rest i was right about...

[sotal]

ok that'll have to do. I think we need this topic pinned though..

Friday 30th September - The Day Fidgits was wrong!!

It could be a national holiday!!

[Fidgits]

it is somewhat embaressing though - considering what i do for a living!

[Jamesb4uk]

Its ok Ian - i'm an IT techie n all so how'd you think I feel lol.

Thanks guys. I'll give it a go tonight when i get home

J

[PaulT]

In summary:

Cloaking your SSID gives you virtually no extra security at all. It can still be discovered.

Filtering on MAC address gives you a small amount of security, but most network drivers these days can spoof any MAC address trivially.

64-bit and 128-bit WEP are much better, (128 is not a huge amount better than 64 but worth having), but if an attacker can get access to about 500000 to one million packets from your network there is a good chance that the encryption can be cracked.

Really it depends how busy your network is, and if you see somebody standing nearby for a few hours looking suspicious ... :D

Change your WEP keys daily if you want to beef up security.

Paul.

[Fidgits]

paul, i have to disagree there - WEP you only need about 5 or 10 minutes to crack if you have the right app off the web ;) And if your office is buiser, then its even easier as (another major flaw in the protocol) everyone uses the same key..

of course, i really shouldn't be risking being wrong again... but in this case i know it to be a fact!

[Demonic Angel]

Bless..... well theres nothing wrong with being wrong once in your life (or maybe twice? )

[Jamesb4uk]

no - ians right on that one - as a security test our company changed the WEP key to 128bit & challenged us to crack it.

one guy cracked it in 30min

J

[knowlson]

it is somewhat embaressing though - considering what i do for a living!

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I am upgrading a wireless install at the mo the wep key was 4 letters

[Fidgits]

it is somewhat embaressing though - considering what i do for a living!

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I am upgrading a wireless install at the mo the wep key was 4 letters

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I knew you would have to comment!

but thats funny! 4 letters!

Knowing you though, theres gonna be a ACL firewall sat behind the access point though!

[Blue84]

One thing that puzzles me with Wireless is the actual network key itself, where do you get that from? does it come with the products?

I'm talking about netgear ones also..

[Fidgits]

No, thats actually fatal flaw #1 in WEP - which is the key is user generated - either through someone making it up - or a 'key generator' which takes a 'code word' and generates a WEP key from it...

The IT manager has to specifiy the key in the router, and then enter the key on all of the laptops so they can have wireless access - and of course, they need to keep a record of the key for new users...

In real security protocols, you have specific software/hardware to generate a truely random key, which has to be a prime number and pass some distinct parameters before it is actually used.. and once you have generated the key, you exchange it securely, and it is only valid for that uni-directional connection for that session...

[knowlson]

I knew you would have to comment! 

but thats funny! 4 letters!   

Knowing you though, theres gonna be a ACL firewall sat behind the access point though! 

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Replaced it with a sonicwall wireless solution I have to say I am impressed integrates IEEE 802.11a/b/g via the main firewall via IPSEC vpn. I am using the sonicpoints and they are all POE. Using the firewalls intrusion prevention system if the sonicpoint is attacked it alerts you to the area being attacked A it's tighter then a mouses ear

[Fidgits]

sweet - I know of sonicwall, and i know the IPSec solution they use very well ;)

sounds a good solid system though!

[knowlson]

;) :D

[Moffmo]

:bookworm:

thanks, iv learnt alot here :D

[Demonic Angel]

I havent I still dont have a clue - its all letters and numbers to me!

[PaulT]

paul, i have to disagree there - WEP you only need about 5 or 10 minutes to crack if you have the right app off the web ;)  And if your office is buiser, then its even easier as (another major flaw in the protocol) everyone uses the same key..

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I chose my words quite carefully, Fidgits :D

You really need to examine of the order of 1m packets to have a good chance of cracking the WEP keys. However, on a 10mbit 11b network with a packet size of approx 1KB, you could easily transfer 1m packets in less than half an hour.

Of course, you may get lucky and see enough weak packets in a few minutes.

However, on a home network you are very unlikely to see that kind of usage unless your machines are constantly gossiping ... which means an attacker would probably take a while to accumulate enough packets in order to crack the keys.

Paul.

[DaveSR]

I havent  I still dont have a clue - its all letters and numbers to me! 

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And thats what a WEP key is ;) !

I use WPA encription........more secure than WEP but it was a pain to set up ;) !

[Fidgits]

paul, i have to disagree there - WEP you only need about 5 or 10 minutes to crack if you have the right app off the web ;)  And if your office is buiser, then its even easier as (another major flaw in the protocol) everyone uses the same key..

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I chose my words quite carefully, Fidgits :D

You really need to examine of the order of 1m packets to have a good chance of cracking the WEP keys. However, on a 10mbit 11b network with a packet size of approx 1KB, you could easily transfer 1m packets in less than half an hour.

Of course, you may get lucky and see enough weak packets in a few minutes.

However, on a home network you are very unlikely to see that kind of usage unless your machines are constantly gossiping ... which means an attacker would probably take a while to accumulate enough packets in order to crack the keys.

Paul.

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fair comment - although in general those weak packets are 'SYN, ACK and SYN-ACK's', which just happen to be the start of any TCP/IP flow, and in a HTTP session, you can have a hellva lot of them - but yes, your explination is sound - its more just general 'home surfing' lends itself to ease of cracking of the key more than corporate which tends to have a more balanced type of packet....

So there you go, we were both right - which is nice :D

[Moffmo]

packet sniffer???

[Fidgits]

packet sniffer???

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Basically its a tool which 'listens' to a network, whether a network cable, or listens for the specific 802.11 radio transmissions..

It then takes a 'copy' of the packet is see's...

think of it like someone 'tapping into a phone call' with a tape recorder - exactly the same principal...

Although the packets are encrypted, they can use them to work out the key.

[PaulT]

fair comment

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High praise there from the master

Paul.