12-12-2024 10:05 AM
Hello,
I've noticed on a few remote switches we are getting:
%CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on GigabitEthernet1/0/1 (10), with switch1. GigabitEthernet1/0/13 (81).
Port Config:
interface GigabitEthernet1/0/1
description Customer Uplink
switchport access vlan 10
switchport mode access
spanning-tree portfast
spanning-tree bpduguard disable
The customer switch linked to ours in on VLAN 81 it seems and we have no access to their switch and the won't change their config or it will be a pain. Can I set out side to use native vlan as 81 and not cause issues? If so what command would that be?
Thanks
12-12-2024 10:14 AM
native vlan is important only in trunk
as I see it access not trunk
can I see
show switchport interface g1/0/1
MHM
12-12-2024 10:21 AM
Switchport: Enabled
Administrative Mode: static access
Operational Mode: static access
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: native
Negotiation of Trunking: Off
Access Mode VLAN: 10 (VLAN0010)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
12-12-2024 10:33 AM
the VLAN is 10 and port is access.
if the remote SW use trunk you need to change the interface into trunk and make native vlan81
you can not config native vlan under access port
MHM
12-12-2024 10:17 AM
Well, unless you have vlan 81, changing the access vlan on your side would probably break it. Best would be to do "no cdp enable" on the port to stop the detection. I believe this should work even though they would still have it enabled on their side.
12-12-2024 10:25 AM
We do need "no cdp enable" for our other switches connected, can I turn it off per port?
12-12-2024 12:12 PM - edited 12-12-2024 12:12 PM
@ajwhite0 wrote:
We do need "no cdp enable" for our other switches connected, can I turn it off per port?
Normally, yes, as already mentioned by @Dustin Anderson's first reply.
12-12-2024 10:17 AM
So, customer is using a trunk and you're using an access port?
Do you have a copy of other side's port config?
As to not causing issues, much depends on how VLANs should be shared between you and your customer.
Should your VLAN 10 be the same VLAN as customer's VLAN 81?
12-12-2024 10:27 AM
No access to their side at all. I've not set this up, but yeah it's an access port out side (posted more output above). If it's an access port it looks like it's just using the native vlan 1. Can I still just set it to 81 with "switch port trunk native vlan 81" even though it's an access port to make the messages go away?
12-12-2024 12:13 PM
@ajwhite0 wrote:
Can I still just set it to 81 with "switch port trunk native vlan 81" even though it's an access port to make the messages go away?
No, for the reason @MHM Cisco World described.
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