07-08-2010 09:01 AM - edited 03-03-2019 05:59 AM
Hi,
I've run in to a problem i cant figure out. Its a live environment and I must be careful not to make things worse, things are working mostly.... I have a link between 2 switches, trunk - dot1q, on one end everything looks fine on the opposite end things don't look right. Things have been working until a couple of weeks ago no changes have been made.
The trunk is NOT carrying all the Vlans (except Vlan 1), when I check spanning-tree it show s the port forwarding all the Vlans. This switch is configured as VTP client, v2, prunning enabled and the down stream switch is transparent.
Any suggestions? thanks inadvance.
show trunk 4/1 detail
* - indicates vtp domain mismatch
# - indicates dot1q-all-tagged enabled on the port
$ - indicates non-default dot1q-ethertype value
Port Mode Encapsulation Status Native vlan
-------- ----------- ------------- ------------ -----------
4/1 nonegotiate dot1q trunking 1
Port Peer-Port Mode Encapsulation Status
-------- --------- ----------- ------------- ------------
4/1 FastEther unknown unknown unknown
Port TrunkFramesTx TrunkFramesRx WrongEncap
-------- -------------------- -------------------- ----------
4/1 119731770 63985591 0
Port Vlans allowed on trunk
-------- ---------------------------------------------------------------------
4/1 1,34,157,166,172,175,178,190,194,504,637,652,804-805,864
Port Vlans allowed and active in management domain
-------- ---------------------------------------------------------------------
4/1 1,34,157,166,172,175,178,190,194,504,637,652,804-805,864
Port Vlans in spanning tree forwarding state and not pruned
-------- ---------------------------------------------------------------------
4/1 1
show spantree 4/1
Port Vlan Port-State Cost Prio Portfast Channel_id
------------------------ ---- ------------- --------- ---- -------- ----------
4/1 1 forwarding 19 32 disabled 0
4/1 34 forwarding 19 32 disabled 0
4/1 157 forwarding 19 32 disabled 0
4/1 166 forwarding 19 32 disabled 0
4/1 172 forwarding 19 32 disabled 0
4/1 175 forwarding 19 32 disabled 0
4/1 178 forwarding 19 32 disabled 0
4/1 190 forwarding 19 32 disabled 0
4/1 194 forwarding 19 32 disabled 0
4/1 504 forwarding 19 32 disabled 0
4/1 637 forwarding 19 32 disabled 0
4/1 652 forwarding 19 32 disabled 0
4/1 804 forwarding 19 32 disabled 0
4/1 805 forwarding 19 32 disabled 0
4/1 864 forwarding 19 32 disabled 0
07-08-2010 10:45 AM
Hi
Can you post trunk config of both switches
Regards
Chetan Kumar
07-08-2010 11:01 AM
This is the down stream switch, where everything looks fine. - Version 12.1(22)EA12, 2950
interface FastEthernet0/26
switchport trunk allowed vlan 1,34,157,166,172,175,178,190,194,504,637,652,804
switchport trunk allowed vlan add 805,864
switchport mode trunk
switchport nonegotiate
end
07-08-2010 11:28 AM
Hi Sean
I think that you had post the output of 6509 ( in intial post ) .
Can you try to configure your 2950 with encap dot1q ( switch port trunk encap dot1q ).
Note : Default it will use Dot1q but before configuring please check the output of 2950 with sh int fa0/26 trunk )
You supposed to see the encap dot1q .
Brelow output :
Port Mode Encapsulation Status Native vlan
fa0/20 on 802.1q trunking 10
and also please check the log in 2950 switch.
Regards
Chetan Kumar
07-08-2010 11:46 AM
Sorry I should have posted this at the begining:
show int fa0/26 trunk
Port Mode Encapsulation Status Native vlan
Fa0/26 on 802.1q trunking 1
Port Vlans allowed on trunk
Fa0/26 1,34,157,166,172,175,178,190,194,504,637,652,804-805,864
Port Vlans allowed and active in management domain
Fa0/26 1,34,157,166,172,175,178,190,194,504,637,652,804-805,864
Port Vlans in spanning tree forwarding state and not pruned
Fa0/26 1,34,157,166,172,175,178,190,194,504,637,652,804-805,864
show spanning-tree int fa0/26
Vlan Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
VLAN0001 Root FWD 19 128.26 P2p
VLAN0034 Root FWD 19 128.26 P2p
VLAN0157 Root FWD 19 128.26 P2p
VLAN0166 Root FWD 19 128.26 P2p
VLAN0172 Root FWD 19 128.26 P2p
VLAN0175 Desg FWD 19 128.26 P2p
VLAN0178 Root FWD 19 128.26 P2p
VLAN0190 Root FWD 19 128.26 P2p
VLAN0194 Desg FWD 19 128.26 P2p
VLAN0504 Root FWD 19 128.26 P2p
VLAN0637 Root FWD 19 128.26 P2p
VLAN0652 Root FWD 19 128.26 P2p
VLAN0804 Root FWD 19 128.26 P2p
VLAN0805 Root FWD 19 128.26 P2p
VLAN0864 Desg FWD 19 128.26 P2p
07-08-2010 12:04 PM
Hi
I'm suspecting vtp pruning on the 6509, and the 2950 is transparent
===> As you mention 2950 is transparent but in output is it showing VTP Client.
Can you explain ?
Regrads
Chetan Kumar
07-08-2010 12:10 PM
Sorry my bad. I wasn't clear - 6509 is client and 2950 is transparent -
2950
show vtp status
VTP Version : 2
Configuration Revision : 0
Maximum VLANs supported locally : 250
Number of existing VLANs : 19
VTP Operating Mode : Transparent
VTP Domain Name : XXXXX
VTP Pruning Mode : Enabled
VTP V2 Mode : Enabled
VTP Traps Generation : Disabled
MD5 digest : XXXXXXXXXXXXXXXXXXXXXXXXXXXX
Configuration last modified by ###.###.###.### at 6-21-10 18:29:17
ResTow>
6509
show vtp domain
Version : running VTP2 (VTP3 capable)
Domain Name : XXXXX Password : configured
Notifications: disabled Updater ID: ###.###.###.###
Feature Mode Revision
-------------- -------------- -----------
VLAN Client 146
Pruning : enabled
VLANs prune eligible: 2-1000
07-14-2010 06:56 AM
The problem has been resolved it was a vtp prunning issue - the solution was to issue a "clear vtp prune-eligible (vlans)" on the upstream switch.
Everything has been working fine since.
07-14-2010 06:57 AM
The problem has been resolved it was a vtp prunning issue - the solution was to issue a "clear vtp prune-eligible (vlans)" on the upstream switch.
Everything has been working fine since.
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