Hello,
I have noticed recently that when I put an interface into 802.1q mode with a native VLAN 1 sub-interface and any number of other VLAN sub-interfaces, that LLDP no longer works.
If I put the interface back in standard IP Routing mode, LLDP works again.
Am I missing something in my config or is this just simply not supported?
Thanks,
Jordan
I think what you mean by "standard IP Routing mode," is this configuration:
Router:
interface <link to switch>
speed 100
full-duplex
encapsulation dot1q
no shutdown
Switch:
interface <uplink to router>
speed 100
full-duplex
switchport mode trunk
no shutdown
interface vlan 1
no ip address
shutdown
interface vlan <not VLAN 1>
ip address 192.168.0.1 255.255.255.0
no shutdown
If no other vlan is designated as native, VLAN 1 becomes the native VLAN by default. It should still send lldp even if it's shut down.
My guess is that you want to do subinterfaces to restrict traffic from the switch to the router. If you have a bigger goal than just seeing lldp, please post that along with a partial configuration from the router interface and the switch (uplinks, VLANs, anything else useful).