WRVS4400Nv2 DHCP Relay on 2nd VLAN

Hi,
Here's what I'm trying to figure out:
My network is set up such that I have a Wireless Network in VLAN 1, which is the primary network that we use. The subnet is 10.5.1.x.
My goal is to set up a completely isolated Guest Wireless Network, however it would work best. What I am trying to do now is I created a seperate VLAN (VLAN 2, IP range 10.5.2.x) and turned on DHCP on the WRVS4400N. However, in the Guest Network, it is always picking up a 10.5.1.x IP which is handed out by the DHCP server (10.5.1.5, Win 2003) and still routing all of the traffic to/from our private network.
Here's What I have set:
Wireless>Security Settings>Guest Network (SSID 2)
Wireless Isolation (between SSID w/o VLAN): Enabled
Wireless Isolation (within SSID): Enabled
Setup>LAN>VLAN 1
Router IP 10.5.1.1, WLAN IP 10.5.1.3
DHCP Relay for 10.5.1.5
Setup>LAN>VLAN 2
Router IP 10.5.2.1
DHCP Enabled for 10.5.2.x subnet
DHCP Relay option is grayed out (not sure why)
Setup>Advanced Routing
Inter-VLAN Routing: Disabled
Any way to solve this would be fine. I just do not want traffic routing through our internal network. Ideally, if I could get the Windows server to hand out 10.5.2.x addresses, that would be perfect, but I'm not sure how to configure it for such.
If anyone has any ideas, that'd be great- thanks!
Matt

Yes...here's an answer I got from Cisco's Engineering support:
The issue you reported is a know issue.
Engineering and development are aware of this issue, and have provided the following information:
PROBLEM DESCRIPTION:
If the WRVS4400N is configured with multiple VLANs, and these VLANs are mapped to different SSID, the user cannot use an external DHCP server to provide IP scopes for these VLANs.
Hosts connected to both SSID will obtain IP address from native DHCP server only.
The workaround for this is to use the embedded DHCP server for all VLANs defined on the WRVS4400N.
Note: This is not considered a bug but rather a product limitation. The developer has confirmed the WRVS4400N is functioning as designed.
Regarding a fix:
Due to wireless and trunk switch port using different chip set, it is not possible to provide a fix for this issue.
In future product, Engineering & Dev teams will strive to use the same chip set (same vendor).
This functionality has been targeted for next new Product. No fix will be made on the current hardware.
Note: If this feature/function is mission critical to your deployment, and you would like to recover the cost of the WRVS4400N, please forward the serial number and a copy of the proof of purchase, and we will gladly provide a refund.
Best regards,
Alex Delano

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###### Extract one ######
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcpProxy: Received packet: Client 00:21:6a:00:35:9c
                        DHCP Op: BOOTREQUEST(1), IP len: 303, switchport: 29, encap: 0xec03
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcp option len, including the magic cookie = 67
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcp option: received DHCP REQUEST msg
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcp option: skipping option 61, len 7
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcp option: requested ip = 10.64.153.66
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcp option: server id = 1.1.1.1
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcp option: skipping option 12, len 12
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcp option: vendor class id = MSFT 5.0 (len 8)
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcp option: skipping option 55, len 12
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcpParseOptions: options end, len 67, actual 67
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcpProxy: dhcp request, client: 00:21:6a:00:35:9c:
                        dhcp op: 1, port: 29, encap 0xec03, old mscb port number: 29
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c Determing relay for 00:21:6a:00:35:9c
                                                                                                        dhcpServer: 10.49.143.8, dhcpNetmask: 0.0.0.0,
                        dhcpGateway: 0.0.0.0, dhcpRelay: 0.0.0.0 VLAN: 0
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c Relay settings for 00:21:6a:00:35:9c
                                                                                                        Local Address: 0.0.0.0, DHCP Server: 10.49.143.8,
                        Gateway Addr: 10.64.153.1, VLAN: 0, port: 29
Tue Mar 9 09:51:31 2010: 00:21:6a:00:35:9c dhcpProcessPacket return an error,chaddr: 00:21:6a:00:35:9c
The process stops working after the last line above. The client reports connection successfully, but no IP address was assigned to the client. A second connection attempt was successful (again – I'll focus on the dhcp REQUEST msg – ignoring DISCOVER, OFFER and ACK msg):
                        DHCP Op: BOOTREQUEST(1), IP len: 303, switchport: 29, encap: 0xec03
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c dhcp option len, including the magic cookie = 67
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c dhcp option: received DHCP REQUEST msg
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c dhcp option: skipping option 61, len 7
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c dhcp option: requested ip = 10.64.153.66
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c dhcp option: server id = 1.1.1.1
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c dhcp option: skipping option 12, len 12
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c dhcp option: vendor class id = MSFT 5.0 (len 8)
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c dhcp option: skipping option 55, len 12
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c dhcpParseOptions: options end, len 67, actual 67
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c dhcpProxy: dhcp request, client: 00:21:6a:00:35:9c:
                        dhcp op: 1, port: 29, encap 0xec03, old mscb port number: 29
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c Determing relay for 00:21:6a:00:35:9c
                                                                                                        dhcpServer: 10.49.143.8, dhcpNetmask: 0.0.0.0,
                        dhcpGateway: 0.0.0.0, dhcpRelay: 10.64.153.6 VLAN: 300
Tue Mar 9 09:53:02 2010: 00:21:6a:00:35:9c Relay settings for 00:21:6a:00:35:9c
                                                                                                        Local Address: 10.64.153.6, DHCP Server: 10.49.143.8,
The major difference seems to be in line 16:
Not Working:
                        dhcpGateway: 0.0.0.0, dhcpRelay: 0.0.0.0 VLAN: 0
Working:
                        dhcpGateway: 0.0.0.0, dhcpRelay: 10.64.153.6 VLAN: 300
For me it seems that the WLC is not able to forward this request to the appropriate dhcp server.
Does anyone of you have an idea, why this happens? And why does this happen only during the first time login of every client? Or am I misinterpreting the debug output?!
Thx a lot in advance!
Cheers
Martin

Hi,
thx for your comment so far.
I did some additional troubleshooting yesterday and I guess I fixed the problem. The management interface was configured with two dhcp server IPs (0.0.0.0 and 1.1.1.1).
Within the Cisco documentation it is stated that the dhcp relay proxy feature uses a virtual IP 1.1.1.1.
0.0.0.0    seems to be used for the internal communication.
When I changed the dhcp address (primary & secondary) to IP 1.1.1.1 the problem was solved. We tested it yesterday evening and this morning.
My assumption is that the virtual 1.1.1.1 IP is mandatory to match the dhcp responses to the proxy relaying feature. Or the WLC uses the DHCP addresses on the management interface to forward the traffic to the appropriate feature (where 1.1.1.1 triggers the proxy feature and 0.0.0.0 is used to forward the traffic to the internal dhcp service). But this is just a guesswork – I do not know the Cisco WLAN good enough to provide a valuable explanation.
Cheers
Martin

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certified the drivers, that's all.
The issues I've seen with DHCP relays and VLANs in the forums are usually based on misconfigs in the VLAN or ports blocked. Sometimes we'll refer to call Microsoft Support for specific, hands-on assistance. And searching the threads, from what
I've found that if they did call support, they've never posted back what the problem was based on or the resolution. I can post a couple of them for you to read through, but there were never any response with the actual resolution.
If you like, you also have the option to contact Microsoft Support. Here's a list of phone numbers if you choose this option:
http://support.microsoft.com/contactus/
Ace Fekay
MVP, MCT, MCITP/EA, MCTS Windows 2008/R2 & Exchange 2007, Exchange 2010 EA, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services
Technical Blogs & Videos: http://www.delawarecountycomputerconsulting.com/
This post is provided AS-IS with no warranties or guarantees and confers no rights.

WRVS4400Nv2 DHCP Relay on 2nd VLAN

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