TKIP Michael MIC problems

cisco

    Sponsored Links

    Next

  • 1. is CDP really layer 2 ?
    My routers are connected each other through Hub with FastEthernet cables. When I looked into cdp packet captured by Ethereal software, I found CDP packet looks like this: IEEE 802.3 Ethernet //layer2 Logical-Link Control //layer3 Cisco Discovery Protocol //layer4 Why CDP protocol is called as layer 2 ? Also if I get CDP packet over serial cable(PPP?), is CDP still layer 2 ? I think PPP protocol is layer 2. I'm so confused. Help me out..
  • 2. VPN with NAT on PIX
    Hi all, I must create a site-to-site VPN with a customer X that has in its internal network the same ip range of my *inside* interface. My VPN peer is a PIX 515 ver 6.2(2). I have already done some tunnels with other customers and I have always used their real private IPs in my encryption domain; the other point is that customer X has to reach few servers in my LAN and probably a static nat is needed. X provides me the subnet it's going to use to NAT its PCs when they search for my servers, so the static NAT should be applied ONLY if the destination belong to customer X range. This is the interfaces list: - inside (192.168.0.0/22) - DMZ (192.168.200.0/24) - alpha (private range) - TELECOM (public range) The overlapping is for inside and DMZ The running configuration about nat is nat (DMZ) 0 access-list NatZeroDmz nat (DMZ) 1 192.168.200.0 255.255.255.192 0 0 global (DMZ) 1 192.168.200.100-192.168.200.253 netmask 255.255.255.0 global (DMZ) 1 192.168.200.254 nat (inside) 0 access-list NatZero nat (inside) 1 0.0.0.0 0.0.0.0 0 0 global (TELECOM) 1 interface Obviousily crypto map is applied on TELECOM Can I manage this new scenario ? Will the changes heavily affect the others connections ? Thank you for your help!
  • 3. N2H2 and URL fiiltering
    All, We have a PIX 515E running 7.0(4), and we're ready to insert it into our network. We also have an N2H2 filter running on a Linux box, and we want the PIX and N2H2 to get along. Configuring the two to cooperate seems fairly straight-forward, at least for the simple configuration we have in mind. But I saw this in the PIX 7.0 Commands.pdf file: The N2H2 server must be a Windows workstation (2000, NT, or XP), running an IFP Server, with a recommended minimum of 512 MB of RAM. What's the deal here? Are they saying they don't want URL filter to be a wimpy machine? Or is Linux strictly forbidden for some reason, and using a Linux based N2H2 server crashes. If the latter, why doesn't the PIX cooperate with N2H2 on Linux? Thanks in advance for any help. B Squared ====================================================================== I read this article. It said the typical symptoms of stress are eating too much, smoking too much, impulse buying, and driving too fast. Are they kidding? This is my idea of a great day! -- Monica Piper
  • 4. Cisco 350AP and 802.1x EAP
    We are currently using stack WEP, and I would like to start using 802.1x with dynamic rotating WEP keys. We are out of maintenance, and we are running 12.02T1 of the VxWorks based OS. I am having trouble getting this to work. I know my Radius server and supplicants are good, because we use the same supplicants and Radius server for our newer wireless system without any problems. I am trying to figure out the right set of configuration options, and I can not get pass the following warning message when a client tries to associate: Station xx:xx:xx:xx:xx Failed Authentication, status "Unsupported Authentication Algorithm". If someone could please guide me in the right direction, I would really appreciate it. Thx. -mike
  • 5. linksys wap54gp ap
    I was looking at the doc's for the Linksys WAP54GP AP. It can have up to 7 wireless vlans but it must be connected to a managed switch to have more than 1 vlan. What to you need (switch wise) to do this?? It really doesn't say or point you in any direction. As far as I can see the AP only has 1 lan port, so how is the managed switch connected?? I'm sure I'm missing something... Thanks

TKIP Michael MIC problems

Postby Fernando Enriquez » Sat, 02 Jul 2005 06:27:51 GMT

Hi everyone:

We've set up a complex installation for one client based on 40 Cisco 
1200 & 1100 APs working as parent-repeater (we have some branches with 
parent-repeater-repeater). We've deployed LEAP on APs and clients both. 
Everything is working fine until any client changes from one AP to 
another. When it starts to transmit traffic it gets blocked because of 
MIC encryption error. The situation remains for a few minutes, when 
suddenly encryption works again.

To minimize impact we have enables key-rotation every 20 seconds but the 
problem remains and users aro not able to work properly.

To validate users we have installed freeradius with leap support. Radius 
log shows that authentication is working fine (no errors)

This is a log excerpt of what happens when client 0040.96a7.c594 
desassociates from AP 192.168.4.207 and associates to AP 192.168.4.200




Re: TKIP Michael MIC problems

Postby Uli Link » Sat, 02 Jul 2005 17:50:48 GMT

Fernando Enriquez schrieb:

It's a feature to block a station after a number of MIC failures.
But this should not happen with allowed, legitimate stations.


What's the fw and driver version of your clients?

For the 350 series the very first fw supporting WPA with TKIP was 5.30.17.

What's the config of your APs? What's the IOS version on you APs?
The 350 series does not work with cipher set to TKIP+WEP (migration mode)

Tip: set up one low traffic AP as WDS, this will allow fast secure roaming.
For 350 clients I prefer CCKM over WPA, you can allow both on a SSID.

-- 
Uli


Re: TKIP Michael MIC problems

Postby Fernando Enriquez » Wed, 06 Jul 2005 00:15:49 GMT

I updated FW on clients and APs both to latest versiones a couple of
weeks ago but problem persists.



Cipher is pure TKIP, not migration mode.



I will try WDS to see if using this the roaming gets smoother. I will
tell you.



Thanks a lot for your interest





Similar Threads:

1.TKIP MIC failures

Hey

Ive got a few AP1200's that Ive just deployed. Most only have 1 or 2
associations right now as Im ramping it up for production.

Ive got 1 client an IBM laptop with an Intel 2200BG card that keeps
causing these errors on the AP.

%DOT11-4-TKIP_MIC_FAILURE_REPORT: Received TKIP Michael MIC failure
report from the station 000e.3568.a238 on the packet (TSC=0x0)
encrypted and protected by pairwise key.

I see these 1 every few minutes, sometimes it will happen more often
and then the radio interface is put on hold and all my WPA clients are
disassociated. All WPA clients diassociated is bad.

%DOT11-3-TKIP_MIC_FAILURE_REPEATED: Two TKIP Michael MIC failures were
detected within 0 seconds on Dot11Radio0 interface. The interface will
be put on MIC failure hold state for next 60 seconds.


So I read some about these messages and they point to someone attackign
my AP but these are being generated by MAC Addrs that are friendly.

Heres the rundown on my setup,  Cisco AP1200's IOS 12.3(2)JA configed
for WPA \TKIP  with a MS IAS RADIUS server backend.

Anyone ever see these errors before ?  Thanks

Timo

2.WPA/TKIP with AP1200

Hi gurus

I'm trying to configure an Windows XP SP1 supplicant with Patch Q815485 
with my laptop HP Nx7010. Initially I work with EAP-TLS + WPA TKIP & 
AP1200, it seems to work fine but after a few seconds the connection is 
broken and supplicant doesn't reconnect with the AP.
HAve you found this issue ?

Can you help me?

Thanks

Manel

3.Cisco ACS 3.3 and Windows 2003 IAS using EAP-TLS and TKIP

I was wondering has anyone every setup using Cisco ACS 3.3 (Radius)
with Windows 2003 IAS to authenicate with PKI cards for wireless and if
so what sets should I follow.  TIA

4.TKIP vs Broadcast Key Rotation

In some of the Cisco documentation, they state that broadcast key rotation
(BKR) "is an excellent alternative to TKIP if your wireless LAN supports
wireless client devices that are not Cisco devices or that cannot be
upgraded to the latest firmware for Cisco client devices."

I don't really understand how this is true. If BKR is only rotating the keys
for broadcast frames, then the user's session (unicast) key isn't touched
by this mechanism, right? So, the classic WEP cracking vulnerabilities
still apply, right?

Must be something I'm missing here... who can enlighten me?

Thanks,
Mike

5.Security of Cisco TKIP implementation on older products

Hello
I am still using Cisco AIR-352 with 12.3(8) IOS as access point, to provide 
connectivity on my wlan ad 802.11b speeds, with WPA-PSK TKIP security.

I have on a site, two AIR-BR352 point to point links at about 4km.
The bridges BR350 uses Wep128 security, and I know that it is unsecure.
On the config pages, I have enable MIC and TKIP settings.

So in the end I have these options enabled:
WEP 128
CISCO MIC
TKIP

This is the extract from cisco's documentations about the two options.


# Message Integrity Check (MIC) -- MIC is an additional WEP security feature 
that prevents attacks on encrypted packets called bit-flip attacks. The MIC, 
implemented on both the access point and all associated client devices, adds 
a few bytes to each packet to make the packets tamperproof.

# Temporal Key Integrity Protocol (TKIP) -- TKIP, also known as WEP key 
hashing, is an additional WEP security feature that defends against an 
attack on WEP in which the intruder uses an unencrypted segment called the 
initialization vector (IV) in encrypted packets to calculate the WEP key.

In the end, these bridges are in WEP128, but are they vulnerable to the 
common wep flaws (IV vector, and vulnerable to airsnort's scans)  ?

To be secure, I use a GRE+IPSEC (at the moment using DES encryption, later I 
will use AES128) tunnel between the two sites connected via the wifi 
bridge, to be more secure.



 

6. Cisco WLC - WPA MIC Errors.....all AP's same syptoms

7. IP phone i2004 audio mic level is low

8. 2 line headset with common mic?



Return to cisco

 

Who is online

Users browsing this forum: No registered users and 97 guest