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iMC topology links! CDP and LLDP

Occasional Advisor

iMC topology links! CDP and LLDP


Since update 7.1 (i think), links have disappeared from the topology map. After update 7.3 i've been playing around with LLDP and CDP discovery of topology links. Our initial deployment of iMC, the topology worked perfect.

In our enviroment, we use HPE 29xx series as access, cisco 3560 as distribution and 4506 as core. Besides that we use several hundreds Nexans switches. Nexans swtiches won't talk CDP to each other, but only to directly connected CDP enabled devices - in our case thats the 3560 switches.

Between our Cisco and HPE devices, when CDP is enabled - links are displayed properly. When LLDP is enabled and CDP is not, all the links on the topology is gone.

We have followed the troubleshooting guide fra HPE, regarding L2 topology discovery, only to verify the LLDP is enabled and that the information is present in iMC. LLDP is working properly on every device.

Are there anybody who has the same problem, or a solution??

Thank in advance,



Esteemed Contributor

Re: iMC topology links! CDP and LLDP

Hello Michael,

I had this issue between HPE Aruba 5400 Switches and could fix it by disabling CDP on the HPE switches with following command:

# no cdp run


After synchronizing the devices the links appear again.

Best Regards,



Ingentive Networks GmbH
Occasional Advisor

Re: iMC topology links! CDP and LLDP

Hi Michael,

I’ve tried turning off CDP at core and distribution layer, but that doesn’t help. Only devices that are discovered via CDP, have their links displayed on the topology map. Despite, that LLDP information are showing correctly on both HP and Cisco devices.

Isn't there are possibilty to open a support case with HPE?