04-27-2008 02:04 PM - edited 03-05-2019 10:38 PM
Hi,
I have 1 3550 and 2 2950 switches connected using a GigaStack Cable using the below setup
3550 (Gigastack to 2950-SW1 and 2950-SW2 using Port Gi0/2)
2950-SW1 to 2950-SW2 using GigaStack(Ports Gi0/1 on both)
I somehow cannot seem to configure a 802.1q trunk on any of the interfaces. DTP doesn't seem to work and even forcing the interfaces to be trunks, they still don't show up in the command "show interfaces trunk".
Is there any special config required for this ?
04-27-2008 02:50 PM
As the only encapsulation available on those switches is 802.1q, you don't need to configure it since that's the default.
You only need to configure it if you have another encapsulation option such as ISL.
You've executed the correct command to verify if you are indeed running 802.1q, which you are.
HTH,
__
Edison.
04-28-2008 04:10 AM
Hi,
That is the problem. Why am I not seeing the interfaces operating in Trunking Mode (Even when they are forced to be)? This config works fine when not using GigaStack.
3550 actually has both ISL and 802.1q and I configured it to use 802.1q to match the other switches.
\\ Naman
04-28-2008 04:22 AM
Please post the output from the following commands:
show inter switchport [module]
show run interface [module]
show interface [module] status
Thanks
__
Edison.
04-28-2008 05:17 AM
Please see below.
+++++++++++++++++++++++++++++++++++
SW03_3550(3550 Switch using Gig0/2. Connected to SW04_2950 and SW05_2950)
================
interface GigabitEthernet0/2
description GIGA STACK
switchport trunk encapsulation dot1q
switchport mode dynamic desirable
end
===========
Name: Gi0/2
Switchport: Enabled
Administrative Mode: dynamic desirable
Operational Mode: static access
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: native
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
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 private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none
=================
sfmc-access-sw03# show interfaces gigabitEthernet 0/2 status
Port Name Status Vlan Duplex Speed Type
Gi0/2 GIGA STACK connected 1 a-half a-1000 1000BaseCX Gigastack
=================
Port Mode Encapsulation Status Native vlan
Gi0/2 desirable 802.1q not-trunking 1
++++++++++++++++++++++++++++++++++++++++++++
SW04_2950 (2950 Switch using Gi0/1- Connected to SW03_3550 and SW05_2950)
====================
interface GigabitEthernet0/1
end
====================
Name: Gi0/1
Switchport: Enabled
Administrative Mode: dynamic desirable
Operational Mode: static access
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: native
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
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 encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none
========================
Port Name Status Vlan Duplex Speed Type
Gi0/1 connected 1 a-half a-1000 1000BaseCX Gigastack
========================
Port Mode Encapsulation Status Native vlan
Gi0/1 desirable 802.1q not-trunking 1
04-28-2008 05:17 AM
<<<<< Continuation From Previous Messages>>
+++++++++++++++++++++++++++++++++++++++++++
SW05_2950 (2950 Switch using Gi0/1- Connected to SW03_3550 and SW04_2950)
======================
interface GigabitEthernet0/1
end
=====================
Name: Gi0/1
Switchport: Enabled
Administrative Mode: dynamic desirable
Operational Mode: static access
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: native
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
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 encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none
=============================
Port Name Status Vlan Duplex Speed Type
Gi0/1 connected 1 a-half a-1000 1000BaseCX Gigastack
=============================
Port Mode Encapsulation Status Native vlan
Gi0/1 desirable 802.1q not-trunking 1
++++++++++++++++++++++++++++++++++++
04-28-2008 06:23 AM
I see what you mean, you want to enable trunking with DTP.
It should work as desirable/desirable should form a trunk.
Have you tried updating the IOS version?
Can you post the output while configured with manual trunking?
__
Edison.
04-28-2008 06:30 AM
Thanks for the quick response.
I can try to see, if we can upgrade.
Output with manual trunking is pretty much the same. The trunks are still 'Not' formed. So even with Trunking manually enabled on all specific ports the the Interfaces remain in Non-Trunking operational mode.
07-13-2009 06:09 AM
mnlatif,
How did you end up fixing this issue. I have 3 3550's (cascading) running 12.2.44 SE6 ipservices and I am having the exact same issue...
Any help would be greatly appreciated.
Thanks in advance.
Mark
07-15-2009 03:35 AM
In case anyone cares, the solution is here -
Page 291.
You must remove config from interface, then shut, config trunking then no shut.
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