Can a lightwitght AP update a Windows 2003 DNS

Steffen Lindemann · ‎02-09-2009

Besides of our WCS to manage all my WLC's and LWAP's we uses CiscoWorks2000 and Solarwinds.

We would like the LWAP's to be tracked (for up and down) in these external tools.

Our LWAP's all uses DHCP and the ideal situation would be that the LWAP's as a part of obtaining the DHCP IP would update the DNS. The external tools could then track on the DNS name, isted of the IP.

The LWAP sends option 12 (RFC 2132) hostname to the DHCP server, but our windows 2003 DHCP/DNS server will update the DNS only if option 81 (RFC 4702) FQDN is set.

I know that we could set the DHCP/DNS server to update all clients, regardless of the option or not. But this does not, because of other reasons.

Does anyone know if I can force the LWAP to send option 81 in the DHCP request?

Best regards,

Steffen Lindemann

jsivulka · ‎02-13-2009

Interface Name................................... management

MAC Address...................................... 00:18:73:36:a0:00

IP Address....................................... 10.10.55.5

IP Netmask....................................... 255.255.255.0

IP Gateway....................................... 10.10.55.1

VLAN............................................. 18

Active Physical Port............................. 1

Primary Physical Port............................ 1

Backup Physical Port............................. Unconfigured

Primary DHCP Server.............................. 192.168.42.130

Secondary DHCP Server............................ Unconfigured

DHCP Option 82................................... Disabled

ACL.............................................. Unconfigured

AP Manager....................................... No

Steffen Lindemann · ‎02-17-2009

This option 82 does not affect the LWAP's DHCP procedure. This option is for adding information to a external DHCP server for the clients connecting to the WLAN's.

http://www.cisco.com/en/US/docs/wireless/controller/5.2/configuration/guide/c52sol.html#wp1063716

What I am looking for is that the LWAP add option 82 (with FQDN) to its DHCP request when the AP is booting.

Our windows environment does not accept to update the DNS based on other methodes (e.g. option 12+15).

richterw81 · ‎03-09-2010

I'm am currently working through this exact situation. If anyone has found a resolution to this please let me know. Thanks.

Scott Fella · ‎03-09-2010

There is no configuration parameter to set that. if you do a

(Cisco Controller) >debug dhcp message enable

Take a look at the log and you will see it skips that option...

(Cisco Controller) >debug dhcp message enable
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option len,
including the magic cookie = 64
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: received DHCP REQUEST msg
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: skipping option 61, len 7
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: requested ip = 10.0.0.1
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: skipping option 12, len 3
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: skipping option 81, len 7
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option:
vendor class id = MSFT5.0 (len 8)
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: skipping option 55, len 11
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcpParseOptions:
options end, len 64, actual 64
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 Forwarding DHCP packet
(332 octets)from 00:40:96:ac:e6:57
-- packet received on direct-connect port requires forwarding to external DHCP server.
Next-hop is 10.0.0.50
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option len,
including the magic cookie = 64
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: received DHCP ACK msg
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: server id = 10.0.0.50
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: lease time (seconds) =86400
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: skipping option 58, len 4
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: skipping option 59, len 4
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: skipping option 81, len 6
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: netmask = 255.0.0.0
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcp option: gateway = 10.0.0.50
Fri Mar 2 16:01:43 2007: 00:40:96:ac:e6:57 dhcpParseOptions:
options end, len 64, actual 64

-Scott
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cburton01 · ‎08-28-2012

I have the exact same issue in our environment with Windows 2008 DHCP and DNS. Every other imaginable device registers a DNS record properly with the exception of the Cisco AP's. The AP's do not appear to be providing FQDN therefore the DNS server is rejecting it according to the audit logs.

I believe that we need the AP to provide the domain name suffix in order to register properly. Anyone successful in correcting this? WIll it do any good to open a TAC case?

Charles

Blending work and play

richterw81 · ‎08-28-2012

It's been 2.5 years since I dealt with this but we did get it to work, my apologies if I don't have the exact information but I do remember the general fix. We did set the DHCP server to always update DNS as mentioned in the first post. It then became a permissions issue with the DHCP server/service account not having permissions to update DNS. After that it worked.

Usefule Microsoft DHCP link:

http://support.microsoft.com/kb/816592

I know this is very general, but I hope it helps.

Wayne