topic You have both AES and TKIP in Wireless

Cisco Aironet 1600 - DHCP Offer Problem

numalliance — Mon, 05 Jul 2021 09:50:38 GMT

Hi,

I have dhcp problem with our new AP:

I add an AP to our LAN.

I make a simple configuration with a WPA authenticate.

I can connect some equipment to this AP and our DHCP give an address correctly.

We use adptator to give wireless connection to old station with old operaing system (adaptator example : Netgear WNCE3001)

This adaptor connect to AP and receive an address from DHCP.

My problem is the equipment behind this adpatator send a DHCP request, our server send a DHCP offer but never arrive to this equipment .....

Same problem with another adpatator (TRENDnet and ZyXEL)

I think Cisco 1600 dont return correctly the DHCP offer, perhaps i miss some configuration.

Anyone can help me ?

Thx

In attachment AP configuration

AP system information:

Product/Model Number:	AIR-SAP1602I-E-K9
Top Assembly Serial Number:	[removed]
System Software Filename:	ap1g2-k9w7-tar.152-2.JB2
System Software Version:	15.2(2)JB2
Bootloader Version:	BOOTLDR: C1600 Boot Loader (AP1G2-BOOT-M) LoaderVersion 15.2(2)JAX, RELEASE SOFTWARE (fc1)

You have both AES and TKIP

Freerk Terpstra — Thu, 02 Apr 2015 21:32:42 GMT

You have both AES and TKIP enabled on the SSID, some clients don't like that "mixed" environment. You also don't use the 802.11a/n radio right now, so basically I would recommend you making this changes to the configuration:

interface Dot11Radio0
 no encryption mode ciphers aes-ccm tkip 
 encryption mode ciphers aes-ccm
 channel least 1 6 11

interface Dot11Radio1
 encryption mode ciphers aes-ccm
 ssid ap-machine-sm
 no shut

Could you give us the output of the "sh dot11 associations" command when the clients are associated but not getting an IPv4 address?

I remove tkip and activate

numalliance — Fri, 03 Apr 2015 09:24:07 GMT

I remove tkip and activate the second wireless interface.

the problem is still there :

1st - the adapter get correct address

ap-speciale-sm#sh dot11 ass
802.11 Client Stations on Dot11Radio0:
SSID [ap-machine-sm] :
MAC Address    IP address      Device        Name            Parent         State
c404.1556.47b3 192.168.1.50    unknown       -               self           Assoc

2nd - we plug the computer behind try to get an address to DHCP server

Apr  3 10:46:43 srv-infra-sm dhcpd: DHCPDISCOVER from 00:1a:a0:12:b5:1a via eth0
Apr  3 10:46:43 srv-infra-sm dhcpd: DHCPOFFER on 192.168.1.80 to 00:1a:a0:12:b5:1a via eth0

Computer never receive this DHCPOFFER

the strange thing is that we see :

ap-speciale-sm#sh dot11 ass
802.11 Client Stations on Dot11Radio0:
SSID [ap-machine-sm] :
MAC Address    IP address      Device        Name            Parent         State
c404.1556.47b3 0.0.0.0    unknown       -               self           Assoc

ap-speciale-sm#sh dot11 ass
802.11 Client Stations on Dot11Radio0:
SSID [ap-machine-sm] :
MAC Address    IP address      Device        Name            Parent         State
c404.1556.47b3 169.254.10.179    unknown       -               self           Assoc

Is a routing problem of mac address ?

We have another AP (Netgear) to another network and this adapter working properly, the computer behind get correctly an address

I think something, perhaps we

numalliance — Fri, 03 Apr 2015 09:28:12 GMT

I think something, perhaps we must parameter something to show that behind this connection there is more then one equipment ?

say to AP it's not just a client but an infra ?

Now that I have googeld on

Freerk Terpstra — Sat, 18 Apr 2015 00:20:32 GMT

Now that I have googeld on your client (Netgear WNCE3001) I really understand want you are trying to accomplish. Want you want is this client acting like something called a workgroup bridge (at least, that is how it is called when you have an Cisco AP fulfilling this role).

With the Cisco deployment you configure the AP as a workgroup bridge with multiple client MAC (and IP) addresses behind it. If the infrastructure where the AP should associated with is non Cisco you can use the "universal mode" where you can just use one (wired) client connected after the AP.

Now back to your Netgear client. I have not seen this client in real life, but if I read the manual I'm getting the feeling that this client does a little more than only bridging. At least there is no option to really configure the workgroup bridge stuff and the WLAN interface is being called "Internet adapter". There is also a option for an LAN DHCP server, which is kinda confusing as well if you ask me.

However, the thing that we can try is using a static IP address on the wired client side and test if communication is possible. Could you please give the output of the "show bridge 1" and "show dot11 ass" commands in that situation? Last but not least you can test if your configuration works after configuring "config network ip-mac-binding disable" on the WLC.