Cisco Trunk port is not getting activated ? please help

[azhar1970]

I have cisco 3560G switch and want to trunk it with a new one Cisco 3560X, 3560G is  configured as given below. I want to configure another trunk on port 14, but it is not going in trunking mode.

aaa session-id common
system mtu routing 1500
ip subnet-zero
ip routing
!
!
!
!
no file verify auto
!
spanning-tree mode rapid-pvst
spanning-tree extend system-id
spanning-tree vlan 10-21 priority 4096
!
vlan internal allocation policy ascending
!
!
interface Port-channel1
 switchport trunk encapsulation dot1q
 switchport mode trunk
!

interface GigabitEthernet0/14
 switchport trunk encapsulation dot1q
 switchport mode trunk
 udld port aggressive
 spanning-tree guard root

interface GigabitEthernet0/22
 description **Connected to NSS-ACC-FLR2-SW1**
 switchport trunk encapsulation dot1q
 switchport mode trunk
 spanning-tree guard root
!
interface GigabitEthernet0/23
 description "Connected to NSS-Core-MZ-Sec"
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode on
!
interface GigabitEthernet0/24
 description "Connected to NSS-Core-MZ-Sec"
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode on
!
interface GigabitEthernet0/25
 description "connected to NSS-ACC-MZ-SW1"
 switchport trunk encapsulation dot1q
 switchport mode trunk
 udld port aggressive
 spanning-tree guard root
!
interface GigabitEthernet0/26
 description "connected to NSS-ACC-MZ-SW2"
 switchport trunk encapsulation dot1q
 switchport mode trunk
 udld port aggressive
 spanning-tree guard root

why its operational mode is down , even cable is connected. 

NSS-Core-MZ-Pri#show interfaces gigabitEthernet 0/14 switchport
Name: Gi0/14
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: down
Administrative Trunking Encapsulation: dot1q
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

[Madhukrishnan Gopinathan Nair]

Hello Azhar,

Can you please share what is the logs generated while the link is not coming up. Also what is the configuration on the other side. I suspect it has something to do with the root guard you have configured on this side. May i know why you need it? Also logs may indicate it well.

Hope this helps.

Thanks,

Madhu

[azhar1970]

Thanks Paul , both side encapsulation is dot1q and will try other options as you stated.

Kind regards

[glen.grant]

  Whats the config of the switch on the other end for port settings ?

[azhar1970]

I have to wait for few days, as remote switch at the site is on hold for configuration. Greatly appreciated all your help, will let you know accordingly in same discussion once I start accessing the same.

greatly appreciated.

[Madhukrishnan Gopinathan Nair]

Thanks Azhar for updating, It will be also a great gesture if you rate all useful posts.

Thanks,

M

[azhar1970]

Root guard is being used at primary (VTP Server end) end but not at (VTP client) end. There are 5 VTP client already trunked and running. 

[Madhukrishnan Gopinathan Nair]

Hello Azhar,

What is the link status when you say it is not coming up in Trunk..Is it err-disbled or not connected?

By default if the other side is explicitly not negotiating the trunk, it should come up automatically.

Ensure both sides are admin up, else i would think this would be a layer 1 issue. Try changing cables, sfp if any etc.

Thanks,

Madhu

[azhar1970]

its showing not connected both sides.

[devils_advocate]

Have you tried removing the trunk configuration and seeing if it comes up as a standard Access Port?

Have you tried manually setting the speed/duplex both sides?

[paul driver]

Hello

Are either side of the trunks using the same encapsulation?
 

can you post:

Sh in trunk
sh int status err-disabled
sh spanning-tree block ports

res

Paul
 

[azhar1970]

Dear Inayat , thanks , let me check it out but by doing shut and no shut , it does not affect anything., will check rest of the things.

1) Let me check without a trunk config, if link gets up.

Thanks.

[InayathUlla Sharieff]

HI,

Can you try this on both the ends:-

{ Enable console logging to see whats happening. ( config t, logging console, exit term monitor)}

Default int X/X,

Config t.

int X/X

shutdown

switchport trunk encapsulation dot1q
 switchport mode trunk 

no shut

.

If still this doesnt work , Check if the link connecting between the two interfaces coming up without the trunk config? 

2- Second if the link is coming back online but after you apply the trunk config the link is staying down, then try disabling the dtp negotiation on both the interfaces .

3- If still the port doesnt come up try doing the self loop and see if the ports comes up or not.

4- If self loop comes up but not between the switches then debug and check whats happening.

HTH

Regards

Inayath

[azhar1970]

In order to make it more clear, I want to say that all other trunks as mentioned above are working, but on port 0/14 that configuration is not working. Which is the same as other switches.