RECV_1Q_NON_TRUNK problem between Cat-4006 and Cat-3560

[CommAdmin]

I found one thread on this site concerning this. It is at

http://www.tek-tips.com/viewthread.cfm?qid=473215.

I could simply turn trunking on, but I want to discover why this is happening when as far as the IOS shows - both ends are not trunking. The new Cat3560 is seeing tagged BPDUs and then blocking Vlan 1 (bad). It doesn't make sense to me since the config items I see say that trunking and tagged bpdus are disabled (on the old 4006). Yet the new 3560 still does this.

The error in the log is shown next:
%SPANTREE-7-RECV_1Q_NON_TRUNK: Received 802.1Q BPDU on non trunk GigabitEthernet0/1 VLAN1.
%SPANTREE-7-BLOCK_PORT_TYPE: Blocking GigabitEthernet0/1 on VLAN0001. Inconsistent port type.
%SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking GigabitEthernet0/1 on VLAN0001. Port consistency restored.

See following config "show" items and see if someone can tell me why this is still happening?

================================================================
The Switch is a Catalyst 3560
================================================================

Cat3560# show interfaces trunk module 1

Port Mode Encapsulation Status Native vlan
Gi0/1 off negotiate not-trunking 1

Port Vlans allowed on trunk
Gi0/1 1

Port Vlans allowed and active in management domain

Port Vlans allowed and active in management domain
Gi0/1 1

Port Vlans in spanning tree forwarding state and not pruned
Gi0/1 1
----------------------------------------------------------------

Cat3560# show interfaces gigabit0/1 trunk

Port Mode Encapsulation Status Native vlan
Gi0/1 off negotiate not-trunking 1

Port Vlans allowed on trunk
Gi0/1 1

Port Vlans allowed and active in management domain
Gi0/1 1

Port Vlans in spanning tree forwarding state and not pruned
Gi0/1 1
----------------------------------------------------------------

Cat3560# show interf gi0/1 etherchannel
Etherchannel not enabled on this port
----------------------------------------------------------------

Cat3560# show spanning-tree interface gi0/1 portfast
VLAN0001 disabled

================================================================
The Switch is a Catalyst 4006
================================================================

Cat4006> (enable) show port trunk
No ports trunking.
Star F> (enable) show trunk 2
* - indicates vtp domain mismatch
# - indicates dot1q-all-tagged enabled on the port
Port Mode Encapsulation Status Native vlan
-------- ----------- ------------- ------------ -----------
2/28 off dot1q not-trunking 1

Port Vlans allowed on trunk
-------- --------------------------------------------------------
2/28 1-1005,1025-4094

Port Vlans allowed and active in management domain
-------- ------------------------------------------------------- 2/28 1

Port Vlans in spanning tree forwarding state and not pruned
-------- ------------------------------------------------------- 2/28
-----------------------------------------------------------------

Cat4006> (enable) show port channel 2
Port Status Channel Admin Ch
Mode Group Id
----- ---------- -------------------- ----- -----
2/27 notconnect auto silent 9 0
2/28 connected auto silent 9 0
2/29 notconnect auto silent 9 0
2/30 notconnect auto silent 9 0
-----------------------------------------------------------------
Cat4006> (enable) show spantree portfast 2/28
Portfast: Default
BPDU Filter: Default
BPDU Guard: Default
Global Portfast BPDU guard is enabled.
Global Portfast BPDU filter is disabled.

 

[VinceWhirlwind]

The config on the facing ports differs in two ways that are immediately obvious:

1/ VLAN allowed: the 3560 allows VLAN 1; the 4000 allows all VLANs

2/ The Trunk encapsulation is set to dot1q on the 4000, but it is set to negotiate on the 3560.

Personally, I would always ensure the facing interface configs match perfectly before trying to put a new link into commission, regardless fo what the show commands might be telling me.

 

[CommAdmin]

You said, "... regardless of what the show commands might be telling me." How would I know the state if they don't show me?

I thought that the trunk mode showing 'off' on the 3560 - meant that it would not form or be a trunk. "Status" does say not-trunking, or is it?

Cat3560# show interfaces trunk module 1
Port Mode Encapsulation Status Native vlan
Gi0/1 >off< negotiate not-trunking 1

On the 3560, would the interface command to turn the negotiation off be: "no switchport trunk encapsulation"?

Having the link be a trunk wouldn't kill me -- I just am curios as to the specific commands that would:
-- Stop the 400x from senging any tagged bpdus at all

Still trying....

 

[VinceWhirlwind]

You know the state if you configure it explicitly.

To not negotiate, you do
sw tr encap dot1q

 

[CommAdmin]

... couldn't see the forest for the trees... ;-\

 

[VinceWhirlwind]

Are you still getting those alerts in the log?

 

[CommAdmin]

I entered the command, and it still gets the same error!!!

Aaargh!

There is still something that is unkind happening...

Sep 20 15:31:16: %SPANTREE-7-RECV_1Q_NON_TRUNK: Received 802.1Q BPDU on non trunk GigabitEthernet0/1 VLAN1.
Sep 20 15:31:16: %SPANTREE-7-BLOCK_PORT_TYPE: Blocking GigabitEthernet0/1 on VLAN0001. Inconsistent port type.
Sep 20 15:31:31: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking GigabitEthernet0/1 on VLAN0001. Port consistency restored.

!
interface GigabitEthernet0/1
description STARF_2/28_VL1
switchport trunk encapsulation dot1q
switchport mode access
switchport nonegotiate
spanning-tree portfast
!

 

[VinceWhirlwind]

What about the "VLAN allowed"? Have you trimmed it down to just the single VLAN?

 

[CommAdmin]

So -- more from the front lines -- Here is the latest news.

****************************************************************
**** Error Log showing the problem before config change ****
****************************************************************
3560_SW# sho logg
Sep 21 16:43:02: %SPANTREE-7-RECV_1Q_NON_TRUNK: Received 802.1Q BPDU on non trunk GigabitEthernet0/1 VLAN1.
Sep 21 16:43:02: %SPANTREE-7-BLOCK_PORT_TYPE: Blocking GigabitEthernet0/1 on VLAN0001. Inconsistent port type.
Sep 21 16:43:17: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking GigabitEthernet0/1 on VLAN0001. Port consistency restored.
3560_SW#

********* Config of port now ***********

4006_SW> (enable) show trunk 2/28
* - indicates vtp domain mismatch
# - indicates dot1q-all-tagged enabled on the port
Port Mode Encapsulation Status Native vlan
-------- ----------- ------------- ------------ -----------
2/28 off dot1q not-trunking 1

Port Vlans allowed on trunk
-------- --------------------------------------------------
2/28 1-1005,1025-4094

Port Vlans allowed and active in management domain
-------- --------------------------------------------------
2/28 1

Port Vlans in spanning tree forwarding state and not pruned
-------- --------------------------------------------------
2/28
4006_SW> (enable)

****************************************************
2 Commands issued to allow only VLAN 1 on this trunk
-- clear trunk 2/28 2-1005
-- clear trunk 2/28 1025-4094
****************************************************

**************** Config showing Vlan 1 allowed ****************

4006_SW> (enable) show trunk 2/28
* - indicates vtp domain mismatch
# - indicates dot1q-all-tagged enabled on the port
Port Mode Encapsulation Status Native vlan
-------- ----------- ------------- ------------ -----------
2/28 off dot1q not-trunking 1

Port Vlans allowed on trunk
-------- ---------------------------------------------------
2/28 1

Port Vlans allowed and active in management domain
-------- ---------------------------------------------------
2/28 1

Port Vlans in spanning tree forwarding state and not pruned
-------- ---------------------------------------------------
2/28
4006_SW> (enable)

*************************************************************
*********** THE CHANGE DID NOT STOP THE PROBLEM ***********
*************************************************************

Sep 21 17:07:50: %SPANTREE-7-RECV_1Q_NON_TRUNK: Received 802.1Q BPDU on non trunk GigabitEthernet0/1 VLAN1.
Sep 21 17:07:50: %SPANTREE-7-BLOCK_PORT_TYPE: Blocking GigabitEthernet0/1 on VLAN0001. Inconsistent port type.
Sep 21 17:08:05: %SPANTREE-2-UNBLOCK_CONSIST_PORT: Unblocking GigabitEthernet0/1 on VLAN0001. Port consistency restored.

What now? Next I'll try dissolving the Channel configuration on the 4006 Switch??? That is the only thing I can see that may have an effect?
-------------------------------------------------------------
2/27 notconnect auto silent 9 0
2/28 connected auto silent 9 0
2/29 notconnect auto silent 9 0
2/30 notconnect auto silent 9 0

 

[CommAdmin]

I've tried all our suggestions and then some, yet the 3560 still displays the error message "%SPANTREE-7-RECV_1Q_NON_TRUNK: Received 802.1Q BPDU on non trunk GigabitEthernet0/1 VLAN1". Taken at face value this means that all the changes and corrections to the 4006 switch configuration did not change the fact that it is sending a tagged BPDU out of it's port connected to the 3560.

I am pasting in below - the current config items on both switches that show the error.

I also have another switch pair. A 4006 channeled to a 3560 - no error messages. The only difference I can see in the configs is that the working config is a 2 port channel. Not a trunk. Still no joy...

===============

3560 Config Items
----------------------------------------------------------------------
3560#show interf trunk module 1
Port Mode Encapsulation Status Native vlan
Gi0/1 off 802.1q not-trunking 1

3560#show int gi0/1 trunk
Port Mode Encapsulation Status Native vlan
Gi0/1 off 802.1q not-trunking 1
Port Vlans allowed on trunk
Gi0/1 1
Port Vlans allowed and active in management domain
Gi0/1 1
Port Vlans in spanning tree forwarding state and not pruned
Gi0/1 1

interface GigabitEthernet0/1
description 4006_2/28_VL1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1
switchport mode access
spanning-tree portfast


======================================================================


4006 Config Items
----------------------------------------------------------------------
show trunk 2/28
* - indicates vtp domain mismatch
# - indicates dot1q-all-tagged enabled on the port
Port Mode Encapsulation Status Native vlan
-------- ----------- ------------- ------------ -----------
2/28 off dot1q not-trunking 1
Port Vlans allowed on trunk
-------- ---------------------------------------------------------------------
2/28 1
Port Vlans allowed and active in management domain
-------- ---------------------------------------------------------------------
2/28 1
Port Vlans in spanning tree forwarding state and not pruned
-------- ---------------------------------------------------------------------
2/28

show runn 2
#module 2 : 34-port 10/100/1000 Ethernet
set port trap 2/1-34 enable
set port name 2/28 To_3560_gi0/1
clear trunk 2/28 2-1005,1025-4094
set trunk 2/28 off dot1q 1
set port channel 2/28 mode off
*set port channel 2/28 111
end

*I put Port 2/28 is into a single admin group for port channel, not that this would change anything... groping.



<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
WORKING SETUP FOLLOWS
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>



A Working 4006 to 3560 pair:

3560 Config Items
----------------------------------------------------------------------
3560#show interf trunk mod 1

Port Mode Encapsulation Status Native vlan
Gi0/47 auto negotiate notrnk-bndl 1
(Po1)
Gi0/48 auto negotiate notrnk-bndl 1
(Po1)
Port Vlans allowed on trunk
Gi0/47 1
Gi0/48 1
Port Vlans allowed and active in management domain
Gi0/47 1
Gi0/48 1
Port Vlans in spanning tree forwarding state and not pruned
Gi0/47 1
Gi0/48 1

3560# show running-config (for gi0/47-48)
interface GigabitEthernet0/47
description Plant Lan Uplink
power inline never
channel-group 1 mode desirable non-silent
!
interface GigabitEthernet0/48
description Plant Lan Uplink
power inline never
channel-group 1 mode desirable non-silent

======================================================================

4006 Config Items
----------------------------------------------------------------------
4006> (enable) show trunk 2/6
* - indicates vtp domain mismatch
Port Mode Encapsulation Status Native vlan
-------- ----------- ------------- ------------ -----------
2/6 auto dot1q not-trunking 1
Port Vlans allowed on trunk
-------- ---------------------------------------------------------------------
2/6 1-1005
Port Vlans allowed and active in management domain
-------- ---------------------------------------------------------------------
2/6 1
Port Vlans in spanning tree forwarding state and not pruned
-------- ---------------------------------------------------------------------
2/6

4006> (enable) show trunk 2/7
* - indicates vtp domain mismatch
Port Mode Encapsulation Status Native vlan
-------- ----------- ------------- ------------ -----------
2/7 auto dot1q not-trunking 1
Port Vlans allowed on trunk
-------- ---------------------------------------------------------------------
2/7 1-1005
Port Vlans allowed and active in management domain
-------- ---------------------------------------------------------------------
2/7 1
Port Vlans in spanning tree forwarding state and not pruned
-------- ---------------------------------------------------------------------
2/7

#module 2 : 34-port 10/100/1000 Ethernet
set port name 2/6 b52a
set port name 2/7 b52a
set spantree portfast 2/3-9,2/11-34 enable
set port channel 2/6-7 mode desirable non-silent