[c-nsp] STP active/listed on wrong port

Tue Mar 12 16:58:20 EDT 2013

Hello,

I would also guess somthing in that direction if it was
general/reproduceble behaviour, but why does that happen only on this port
?
I have lots of ports with similar config (mode trunk, everything tagged)
on several boxes and this is the only one listed in "show spanning-tree".

Config samples:

interface GigabitEthernet7/2
 switchport
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 666,1153
 switchport mode trunk
 load-interval 30
end

interface GigabitEthernet7/16
 description custsw2-dus1 A16
 switchport
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1253,1606
 switchport mode trunk
 mtu 9216
 load-interval 30
end

interface TenGigabitEthernet8/2
 switchport
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1122,1142,1293,1421,1429,1476,3404,3405
 switchport trunk allowed vlan add 3408-3410
 switchport mode trunk
 mtu 9216
 load-interval 30
end

Only 7/16 is listed and there is nothing on the config beside the above as
far as I see:

edge1-dus3#sh running-config | inc 7/16
interface GigabitEthernet7/16
edge1-dus3#

kind regards
Rolf

> You're using 802.1q, which uses an untagged native VLAN for things like
> STP
> BPDUs, CDP, VTP, etc ,etc.  Even though you pruned off VLAN 1 via the
> allowed VLANs command, the native VLAN will still be used for
> switch-generated protocols like those listed above.  Only transit-traffic
> is
> denied by pruning.  If you change the native VLAN to something other than
> one (do it on both sides, or wacky/painful things can happen), you should
> see VLAN 1 no longer on that port.
>
> Chuck
>
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net
> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of "Rolf Hanßen"
> Sent: Tuesday, March 12, 2013 1:34 PM
> To: cisco-nsp at puck.nether.net
> Subject: [c-nsp] STP active/listed on wrong port
>
> Hello list,
>
> do you have an explanation why STP thinks Gi7/16 belongs to vlan 1 ?
>
> edge1-dus3#sh spanning-tree
>
> VLAN0001
>   Spanning tree enabled protocol ieee
>   Root ID    Priority    32769
>              Address     5475.d0a6.75c0
>              This bridge is the root
>              Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
>
>   Bridge ID  Priority    32769  (priority 32768 sys-id-ext 1)
>              Address     5475.d0a6.75c0
>              Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
>              Aging Time 300
>
> Interface           Role Sts Cost      Prio.Nbr Type
> ------------------- ---- --- --------- --------
> --------------------------------
> Gi7/16              Desg FWD 4         128.1552 P2p
>
>
> Interface Config:
> interface GigabitEthernet7/16
>  description custsw2-dus1 A16
>  switchport
>  switchport trunk encapsulation dot1q
>  switchport trunk allowed vlan 1253,1606  switchport mode trunk  mtu 9216
> load-interval 30 end
>
> STP is disabled on all other vlans:
> no spanning-tree vlan 2-4000
>
> Gi7/16 is not listed here:
>
> edge1-dus3#sh vlan id 1
>
> VLAN Name                             Status    Ports
> ---- -------------------------------- ---------
> -------------------------------
> 1    default                          active    Gi1/5, Gi1/8, Gi1/13,
> Gi1/25, Gi1/27, Gi1/48, Te4/1, Gi6/1, Gi7/1, Gi7/3, Gi7/4, Gi7/5, Gi7/6,
> Gi7/7, Gi7/8, Gi7/9, Gi7/10, Gi7/11, Gi7/12, Gi7/13, Gi7/14, Gi7/15,
> Gi7/17,
> Gi7/18, Gi7/19
>                                                 Gi7/20, Gi7/21, Gi7/22,
> Gi7/23, Gi7/24
>
> VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1
> Trans2
> ---- ----- ---------- ----- ------ ------ -------- ---- -------- ------
> ------
> 1    enet  100001     1500  -      -      -        -    -        0      0
>
> Remote SPAN VLAN
> ----------------
> Disabled
>
> Primary Secondary Type              Ports
> ------- --------- -----------------
> ------------------------------------------
>
>
> Port is up and works fine:
>
> edge1-dus3#sh int Gi7/16
> GigabitEthernet7/16 is up, line protocol is up (connected)
>   Hardware is C6k 1000Mb 802.3, address is 001d.a246.3743 (bia
> 001d.a246.3743)
>   Description: custsw2-dus1 A16
>   MTU 9216 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
>      reliability 255/255, txload 6/255, rxload 6/255
>   Encapsulation ARPA, loopback not set
>   Keepalive set (10 sec)
>   Full-duplex, 1000Mb/s, media type is LX
>   input flow-control is off, output flow-control is off
>   Clock mode is auto
>   ARP type: ARPA, ARP Timeout 04:00:00
>   Last input 00:00:00, output never, output hang never
>   Last clearing of "show interface" counters never
>   Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
>   Queueing strategy: fifo
>   Output queue: 0/40 (size/max)
>   30 second input rate 27117000 bits/sec, 3517 packets/sec
>   30 second output rate 24383000 bits/sec, 2860 packets/sec
>      32078138057 packets input, 32998390284372 bytes, 0 no buffer
>      Received 524965 broadcasts (173874 multicasts)
>      0 runts, 0 giants, 0 throttles
>      0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
>      0 watchdog, 0 multicast, 0 pause input
>      0 input packets with dribble condition detected
>      13839785752 packets output, 9991981200426 bytes, 0 underruns
>      0 output errors, 0 collisions, 3 interface resets
>      0 unknown protocol drops
>      0 babbles, 0 late collision, 0 deferred
>      0 lost carrier, 0 no carrier, 0 pause output
>      0 output buffer failures, 0 output buffers swapped out
>
>
> edge1-dus3#sh version
> Cisco IOS Software, c7600s72033_rp Software
> (c7600s72033_rp-ADVIPSERVICESK9-M), Version 15.1(2)S, RELEASE SOFTWARE
> (fc1)
>
> Hardware is Cisco 7609-S, Sub720-3BXL, Slot 7 is a WS-X6724-SFP
>
> kind regards
> Rolf Hanßen
>
>
>
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