Yes, that is a very interesting find on CDP. It would be nice if CDP was coded to operate in the same way on Cisco devices J
As for not seeing the CDP, what do you see when you run show cdp interface on both sides? Jason Boyers - CCIE #26024 (Wireless) Technical Instructor - IPexpert, Inc. Mailto: <mailto:[email protected]> [email protected] From: Leigh Jewell [mailto:[email protected]] Sent: Tuesday, September 20, 2011 11:00 PM To: Brendon Hwang Cc: Jason Boyers; [email protected] Subject: Re: [OSL | CCIE_Wireless] Vlan 1 on trunks for CDP Thanks Jason.. Interesting find Brendon. The thing is, currently I cannot get CDP to be seen over the Dot11Radio interface even though in a debug I can see the packets been sent. BR_1# *Mar 1 21:08:02.526: CDP-PA: version 2 packet sent out on Dot11Radio1 *Mar 1 21:08:13.526: CDP-PA: version 2 packet sent out on Virtual-Dot11Radio0 *Mar 1 21:08:31.526: CDP-PA: version 2 packet sent out on FastEthernet0 *Mar 1 21:08:37.551: CDP-PA: Packet received from 6504 on interface FastEthernet0 BR_2# *Mar 2 02:21:33.947: CDP-PA: Packet received from CAT4 on interface FastEthernet0.10 On 21 September 2011 12:23, Brendon Hwang <[email protected]> wrote: Just add one thing.. may be useful.. Looked at the user guide to refresh.. http://www.cisco.com/en/US/docs/wireless/access_point/12.4_3g_JA/configurati on/guide/s43cdp.html "CDP is sent on the lowest VLAN number configured on the access point. When more than one VLAN is used in a wireless network, Cisco recommends that the lowest VLAN number configured be used as the native VLAN" Cheers, Brendon On 21/09/2011, at 12:20 AM, Jason Boyers wrote: CDP will operate, even if VLAN 1 is not allowed on a trunk interface. It is sent as an untagged frame from one device to another, even if the native VLAN (whatever it is) is not allowed on the trunk. Try this for a test: 1. Cable a connection between 2 switches 2. Configure another VLAN (say 10) on those switches 3. Configure the switchport on each of those switches used to connect to each other as a trunk port, with the VLAN from #2 as native 4. Only allow another VLAN which has not been configured on the switch (say VLAN 999) to pass between the switches The switches will still see one another as CDP neighbors. You can verify the CDP packets are passing with the debug cdp packets command. It won't matter what VLAN is set as native or allowed. Jason Boyers - CCIE #26024 (Wireless) Technical Instructor - IPexpert, Inc. Mailto: <mailto:[email protected]> [email protected] From: [email protected] [mailto:[email protected]] On Behalf Of Leigh Jewell Sent: Tuesday, September 20, 2011 1:19 AM To: [email protected] Subject: [OSL | CCIE_Wireless] Vlan 1 on trunks for CDP Is anyone leaving vlan 1 on WLC trunks for CDP to operate ? Cheers, Leigh _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com
_______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com
