DHCP assignment through a Ethernet Bridge

stephane.rouiller · ‎05-30-2008

Hello,

I have a Cisco WLC4402 with several AP 1240 LWAPP Serie.All works fine but I have a problem if I use DHCP assignment

through a Linksys bridge WET200 (version 1.0.10), the laptop doesn't receive an IP address. But, if I configure a static IP the connectivity is good.

The debug dhcp packet command on the WLC returns :

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP received op BOOTREQUEST (1) (len 308, port 1, encap 0xec03)

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP selecting relay 1 - control block settings:

dhcpServer: 172.23.4.27, dhcpNetmask: 0.0.0.0,

dhcpGateway: 0.0.0.0, dhcpRelay: 172.23.17.20 VLAN: 0

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP selected relay 1 - 172.23.4.27 (local address 172.23.17.20, gateway 172.23.17.13, VLAN 0, port 1)

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP transmitting DHCP DISCOVER (1)

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP op: BOOTREQUEST, htype: Ethernet, hlen: 6, hops: 1

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP xid: 0x91462014 (2437292052), secs: 0, flags: 8000

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP chaddr: 00:16:d5:1f:12:26

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP ciaddr: 0.0.0.0, yiaddr: 0.0.0.0

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP siaddr: 0.0.0.0, giaddr: 172.23.17.20

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP sending REQUEST to 172.23.17.13 (len 346, port 1, vlan 0)

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP selecting relay 2 - control block settings:

dhcpServer: 172.23.4.27, dhcpNetmask: 0.0.0.0,

dhcpGateway: 0.0.0.0, dhcpRelay: 172.23.17.20 VLAN: 0

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP selected relay 2 - NONE

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP received op BOOTREPLY (2) (len 344, port 1, encap 0xec00)

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP sending REPLY to STA (len 444, port 1, vlan 0)

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP transmitting DHCP OFFER (2)

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP op: BOOTREPLY, htype: Ethernet, hlen: 6, hops: 0

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP xid: 0x91462014 (2437292052), secs: 0, flags: 8000

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP chaddr: 00:16:d5:1f:12:26

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP ciaddr: 0.0.0.0, yiaddr: 172.23.17.31

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP siaddr: 0.0.0.0, giaddr: 0.0.0.0

Fri May 30 07:09:30 2008: 00:16:d5:1f:12:26 DHCP server id: 10.2.3.1 rcvd server id: 172.23.4.27

Wireshark shows that the Laptop send a DHCP discover but never reserve an answer.

On the Linksys bridge, I use the Cloning Feature in Auto Mode.

Why the laptop can't retrieve a IP address if it is connected through this Ethernet bridge?

bwilmoth · ‎06-05-2008

Have a look at this bug:CSCdp20709

rajinder63 · ‎06-18-2008

even i am facing the same problem with the ethernet Bridge , my Laptop doesn't getting the ip address from the dhcp ... I have configured the Dhcp on WlC it self .. here is the debug og DHCP

(Cisco Controller) >

(Cisco Controller) >Tue Jun 17 06:08:41 2008: 00:00:00:00:00:00 dhcpProxy: Received packet: Client 00:00:00:00:00:00

DHCP Op: BOOTREQUEST(1), IP len: 356, switchport: 2, encap: 0xec00

Tue Jun 17 06:08:41 2008: 00:00:00:00:00:00 dhcpProxy: Dropping packet (no mscb) from STA 00:00:00:00:00:00, giaddr:0.0.0.0, udpSrcPort:4002, op:1

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b dhcpProxy: Received packet: Client 00:15:c5:40:a7:0b

DHCP Op: BOOTREQUEST(1), IP len: 300, switchport: 2, encap: 0xec03

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b dhcpProxy: dhcp request, client: 00:15:c5:40:a7:0b:

dhcp op: 1, port: 2, encap 0xec03, old mscb port number: 2

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b Determing relay for 00:15:c5:40:a7:0b

dhcpServer: 150.158.73.6, dhcpNetmask: 0.0.0.0,

dhcpGateway: 0.0.0.0, dhcpRelay: 192.168.0.250 VLAN: 20

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b Relay settings for 00:15:c5:40:a7:0b

Local Address: 192.168.0.250, DHCP Server: 150.158.73.6,

Gateway Addr: 192.168.0.251, VLAN: 20, port: 2

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b DHCP Message Type received: DHCP DISCOVER msg

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b op: BOOTREQUEST, htype: Ethernet, hlen: 6, hops: 1

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b xid: 279088047, secs: 0, flags: 8000

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b chaddr: 00:15:c5:40:a7:0b

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b ciaddr: 0.0.0.0, yiaddr: 0.0.0.0

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b siaddr: 0.0.0.0, giaddr: 192.168.0.250

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b dhcpProxy: Received packet: Client 00:15:c5:40:a7:0b

DHCP Op: BOOTREPLY(2), IP len: 548, switchport: 0, encap: 0x0

Tue Jun 17 06:08:42 2008: DHCP Reply to AP client: 00:15:c5:40:a7:0b, frame len 412, switchport 2

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b DHCP Message Type received: DHCP OFFER msg

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b op: BOOTREPLY, htype: Ethernet, hlen: 6, hops: 0

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b xid: 279088047, secs: 0, flags: 8000

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b chaddr: 00:15:c5:40:a7:0b

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b ciaddr: 0.0.0.0, yiaddr: 192.168.0.145

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b siaddr: 0.0.0.0, giaddr: 0.0.0.0

Tue Jun 17 06:08:42 2008: 00:15:c5:40:a7:0b server id: 1.1.1.1 rcvd server id: 150.158.73.6

Tue Jun 17 06:08:45 2008: 00:15:c5:40:a7:0b dhcpProxy: Received packet: Client 00:15:c5:40:a7:0b

DHCP Op: BOOTREQUEST(1), IP len: 300, switchport: 2, encap: 0xec03

Tue Jun 17 06:08:45 2008: 00:15:c5:40:a7:0b dhcpProxy: dhcp request, client: 00:15:c5:40:a7:0b: