WISM module and DHCP relay

Unanswered Question
Dec 5th, 2007

Hi,

I'm in the process of testing wireless connectivity via a light weight WAP that communicates with the WISM module ( currently running 4.0.206.0). However i've noticed that the wireless client doesn't pick up an IP via DHCP although the IP helper addresses, i.e. the DHCP servers are configured for the wireless VLAN. This is evidenced by not seeing a DHCP DISCOVER message in the DHCP logs for my MAC address.

From reading the config guide there is mention of the WISM acting as a DHCP relay agent, and the fact that this is tied to the virtual IP. Currently the IP is set to 1.1.1.1 as per the config guide. Does this need to change? What can be done to address this issue?

Any suggestions welcome.

thanks

Sheldon

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Loading.
sgonsalv Wed, 12/05/2007 - 21:57

JUST TO ADD MORE INFO:

The Virtual IP being used is 1.1.1.1 which doesn't appear anywhere on the network, and isn't tied to any VLAN configured on the network. So the IP is completely isolated.

From reading the config notes, it asks for a DNS gateway hostname. Here i've configured the DNS server used on the client machines.

But as explained above, the wireless client can't obtain an IP via DHCP for the Wireless VLAN

sgonsalv Wed, 12/05/2007 - 22:55

SOME MORE TO ADD:

When i manually set an IP for the clients, all IP connectivity is fine. So the only issue here is DHCP.

I've disabled the WISM from acting as a DHCP proxy, so that all DHCP info goes via the WISM untouched. But since there is no DISCOVER message seen, looks like the WISM isn't passing the SHCP info properly.

rmerritt Fri, 12/07/2007 - 19:04

You probably know this but on your DHCP scope, have you set the advanced options for Cisco LWAPP?

pmccubbin Sat, 12/08/2007 - 05:38

Hi Sheldon,

To add to what Ray mentioned, did you configure Option 43 on your DHCP server?

Take a look here:

http://www.cisco.com/en/US/docs/wireless/access_point/1500/installation/guide/1500_axg.html

If you don't have Option 43 configured on the subnet for your LWAPPs then they won't be able to receive an IP address. Your PC would be able to receive an IP but not the LWAPP.

Hope this helps and that you rate all posts which you find useful.

Best,

Paul

Actions

This Discussion

 

 

Trending Topics: Other Wireless Mobility

client could not be authenticated
Network Analysis Module (NAM) Products
Cisco 6500 nam
reason 440 driver failure
Cisco password cracker
Cisco Wireless mode