WLC 2504+Vmware Bridge mode - DHCP dropping packet (no mscb) found.

sardarjion — Wed, 30 Nov 2022 16:56:22 GMT

I have the following setup:

RVS4000 router giving IP addresses
WLC 2504 v8.3.150.0 with AP 2702 and 1142 connected in lightweight mode
Windows 10 machine connecting to network via WiFi - HostName (Win10PhysicalHost) - IP (192.168.1.5)
Point 3 machine running Vmware player 16 running another instance of Windows 10 and network adapter set to bridge mode - HostName (DESKTOP-BEJ55KK) - DHCP request failing at WLC level.

DHCP Proxy is disabled on WLC. Even enabling this setting didn't help. Also no special DHCP configured for the SSID.

When I boot the machine, the first step is physical machine to get the IP addrdress and in wireshark I see DHCP message going back and forth and physical host getting assigned IP 192.168.1.5.

Vmware boots the virtual machine and connects in "Bridge Mode" over the wifi network. Here, the DHCP request goes out to controller and further to the DHCP server but the response seems to be dropped by WLC although DHCP assigned the IP address to virtual machine (192.168.1.130).

*DHCP Socket Task: Nov 30 01:29:34.605: 00:0c:29:fa:ba:42 DHCP option: message type = DHCP REQUEST
*DHCP Socket Task: Nov 30 01:29:34.605: 00:0c:29:fa:ba:42 DHCP option: 61 (len 7) - skipping
*DHCP Socket Task: Nov 30 01:29:34.605: 00:0c:29:fa:ba:42 DHCP option: requested ip = 192.168.1.130
*DHCP Socket Task: Nov 30 01:29:34.605: 00:0c:29:fa:ba:42 DHCP option: hostname = DESKTOP-BEJ55KK (len 15)
*DHCP Socket Task: Nov 30 01:29:34.605: 00:0c:29:fa:ba:42 DHCP option: 81 (len 18) - skipping
*DHCP Socket Task: Nov 30 01:29:34.605: 00:0c:29:fa:ba:42 DHCP option: vendor class id = MSFT 5.0 (len 😎
*DHCP Socket Task: Nov 30 01:29:34.605: 00:0c:29:fa:ba:42 DHCP option: 55 (len 14) - skipping
*DHCP Socket Task: Nov 30 01:29:34.605: 00:0c:29:fa:ba:42 DHCP options end, len 94, actual 86
*DHCP Socket Task: Nov 30 01:29:34.605: 00:0c:29:fa:ba:42 DHCP dropping packet (no mscb) found - (giaddr 0.0.0.0, pktInfo->srcPort 68, op: 'BOOTREQUEST')
*dtlArpTask: Nov 30 01:29:34.906: f0:1d:bc:f1:b1:9b In apfMsDhcpStateClear for station f0:1d:bc:f1:b1:9b to clear dhcp flag
*dtlArpTask: Nov 30 01:29:34.907: f0:1d:bc:f1:b1:9b Assigning Address 192.168.1.130 to mobile

I tried the same configuration using LAN cable and everything works fine and virtual machine gets the IP address.

On WLC, it says option 61 is skipped and I think that might make a difference because WLC might be thinking same host is asking for IP again. In wireshark, I see these two different values in option 61.

Physical Host:

Virtual machine:

In wireshark, this is how the DHCP transactions look for

Wireless - Failure case

Wired - Success case

Adding console output log capturing DHCP packets.

Re: WLC 2504+Vmware Bridge mode - DHCP dropping packet (no mscb) found

Rich R — Thu, 01 Dec 2022 17:43:24 GMT

Have you tried this: https://www.ciscozine.com/allow-multi-ip-address-from-wireless-client/

Re: WLC 2504+Vmware Bridge mode - DHCP dropping packet (no mscb) found

Scott Fella — Thu, 01 Dec 2022 17:50:48 GMT

The post @Rich R provided is correct. You need passive client anytime you are running a hyper visor on a wireless machine. Good test is to set the nic on NAT mode and make sure that works as far as reachability, then passive mode to allow dhcp to be obtained through the host machine.

Re: WLC 2504+Vmware Bridge mode - DHCP dropping packet (no mscb) found

sardarjion — Mon, 05 Dec 2022 07:22:52 GMT

Thanks you so much Rich. This indeed fixed the issue on the virtual machine.

I am just wondering if there is a reason why this setting is not default when the SSID is created?

topic Re: WLC 2504+Vmware Bridge mode - DHCP dropping packet (no mscb) found in Wireless

WLC 2504+Vmware Bridge mode - DHCP dropping packet (no mscb) found.

Re: WLC 2504+Vmware Bridge mode - DHCP dropping packet (no mscb) found

Re: WLC 2504+Vmware Bridge mode - DHCP dropping packet (no mscb) found

Re: WLC 2504+Vmware Bridge mode - DHCP dropping packet (no mscb) found