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Author Topic: Block Cisco CDP on Nortel/Avaya 5520  (Read 3794 times)

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Offline Alz

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Block Cisco CDP on Nortel/Avaya 5520
« on: March 21, 2014, 04:35:36 AM »
I have a Nortel/Avaya 5520-48T PWR running 6.3
I have a number of Cisco Devices and Cisco servers attached
The Avaya switch does not recognize Cisco Discovery Protocol (CDP) so it allows the frames to traverse the switch backplane
CDP is of no use if it crosses port boundaries.
I need a way to block all CDP packets from the Cisco devices. I can turn off the CDP from each Cisco
device but it is difficult since I have over 20+ devices.
Is there a way to block CDP on the switch ports?


Alz


Offline Flintstone

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Re: Block Cisco CDP on Nortel/Avaya 5520
« Reply #1 on: March 21, 2014, 08:38:17 AM »
Hi Alz,

I believe CDP uses multicast, so the best way would be to disable CDP on a per interface or Cisco device?

CheerZ

Offline Alz

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Re: Block Cisco CDP on Nortel/Avaya 5520
« Reply #2 on: March 21, 2014, 11:48:35 AM »
Turning off CDP on every Cisco Phone is not scalable. It would turn into an administrative nightmare
Is there a way to block the multicast mac address or block the CDP ethertype from entering the switch ports?


anyone have experience with this?
I would think anyone would want to use this with a mixed vendor network

Nigel

Offline Paul L

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Re: Block Cisco CDP on Nortel/Avaya 5520
« Reply #3 on: March 21, 2014, 11:00:24 PM »
if you can find the ether type you can create a filter or l2 classifier.

wouldn't be that hard.
ACSS- Avaya Enterprise Routing Switch  #8

Offline Alz

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Re: Block Cisco CDP on Nortel/Avaya 5520
« Reply #4 on: April 08, 2014, 03:19:04 PM »
I found out the CDP info

ether host 01:00:0c:cc:cc:cc and ether[16:4] = 0x0300000C and ether[20:2] == 0x2000

so i decided to try to create the l2-acl to drop the l2 frames
On the switch I get the following error

5520-48T-PWR(config)#$qos l2-acl Blockcdp dst-mac 01:00:0c:cc:cc:cc
% Cannot modify settings
% Unable to install access element - component creation issue

The switch config is pretty basic with only a few vlans and running 6.3 code.
I saw that you can only have 16 classifiers but I haven't configured any yet and I am being blocked

***************************************************************
  *** Ethernet Routing Switch 5520-48T-PWR                    ***
  *** Avaya                                                   ***
  *** Copyright (c) 1996-2013,  All Rights Reserved           ***
  ***                                                         ***
  *** HW:34       FW:6.0.0.18  SW:v6.3.3.040                  ***
  ***************************************************************