Re: why LLDP showing for subinterface

jigojar · ‎08-12-2022

Hi Team,

We are finding that lldp neighbor entry is visible for the subinterface(vlan interface). how to avoid the lldp neighbor for the subinterface alone?

GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.198 104
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.145 104
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.719 104
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.455 104
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.626 104
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.708 105
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.722 105
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.712 106
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.267 106
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.166 107
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.158 107
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.650 107
GE0/0/26 TN-RMD-RSM-T3-ST-SBE-... Gi0/0/0.610 107

MHM Cisco World · ‎08-12-2022

Instead of config lldp in global mode config it under one subinterface,

Or

Disable the lldp on all subinterface except one.

jigojar · ‎08-16-2022

is it possible to enable the lldp only for the global interface. need solution to enable the lldp only on main interface.

MHM Cisco World · ‎08-17-2022

try same disble the LLDP under all sub interface and enable it under main interface

Georg Pauwen · ‎08-17-2022

@MHM Cisco World Out of curiosity, since I did not get this to work: on what device and IOS is this working fro you ?

MHM Cisco World · ‎08-17-2022

Hi @Georg Pauwen
I ask him try myself not try it.

is this can done in Main interface Yes it can,
the CDP and I think same is LLDP using special behave for subinterface,
the cisco Doc. mention that if the router does not have VLAN1 config and any of the subinterface is config w/wo native keyword the packet traverse over the main interface

for more detail please check this doc.
https://www.cisco.com/c/en/us/support/docs/network-management/discovery-protocol-cdp/118736-technote-cdp-00.html

paul driver · ‎08-16-2022

Hello
LLDP is enable globally, so you need to turn it off at an interface level

Please rate and mark as an accepted solution if you have found any of the information provided useful.
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Kind Regards
Paul

Georg Pauwen · ‎08-17-2022

Hello,

as far as I recall, you cannot disable LLDP on subinterfaces only. If you disable it on one subinterface, it will be disabled altogether, for all subinterfaces, as well as for the physical interface. I just tested this on a 16.x IOS, not sure what the behaviour is in higher versions...