[c-nsp] having a one-way vlan 1 stp issue....

Aaron aaron1 at gvtc.com
Thu Sep 6 11:36:08 EDT 2012


Any idea why I can only see spanning tree for vlan 1 in *one direction* ?
all other vlan's stp work fine.  AND if I flip the stp priority to prefer
root bridge placement on CE2 IT WORKS!  See below.  (also bidirectional
flows work for vlan 1 pings, vtp and cdp)  ONLY STP VLAN 1 is broke in one
direction ...that's the only problem I'm seeing.

Aaron

(topology)

CE2 (3750) g1/0/1 trunk all-----------g0/23
(me3600)---mpls-----(asr9k)g0/0/0/9/.116----- trunk all  g1/0/1 (3750) CE1

(configs)

----------------------
----- CE2
----------------------

ce2-realnoc#sh run in g1/0/1

interface GigabitEthernet1/0/1
 switchport trunk encapsulation dot1q
 switchport mode trunk
end

----------------------
---- PE (3600)
----------------------

noc-3600#sh run in g0/23

interface GigabitEthernet0/23
 description c7 tls-test
 switchport trunk allowed vlan none
 switchport mode trunk
 load-interval 30
 service instance 1 ethernet
  encapsulation dot1q 1-4094
  l2protocol tunnel cdp stp vtp dtp pagp lldp lacp udld
  xconnect 10.101.0.3 20000 encapsulation mpls

----------------------
----- PE (asr9k)
----------------------

RP/0/RSP0/CPU0:sv-b-9k#sh run l2vpn xconnect group tls-test

l2vpn
 xconnect group tls-test
  p2p tls-test
   interface GigabitEthernet0/0/0/9.116
   neighbor 10.101.12.253 pw-id 20000

----------------------
----- CE1
----------------------

ce1-top-crml#sh run in g1/0/1

interface GigabitEthernet1/0/1
 switchport trunk encapsulation dot1q
 switchport mode trunk
end


(what I'm seeing)

CE2  <<<----------- stp broke in this direction ONLY FOR VLAN 1 --------
CE1  (from ce1 to ce2)

Ce2 *doesn't* see vlan 1 config bpdu's carrying superior bridge prio of 8193
!!


ce2-realnoc#sh sp roo

                                        Root    Hello Max Fwd
Vlan                   Root ID          Cost    Time  Age Dly  Root Port
---------------- -------------------- --------- ----- --- ---  ------------
VLAN0001         32769 68bc.0c61.3a80         0    2   20  15
VLAN0010          8202 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0020          8212 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0021          8213 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0022          8214 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0023          8215 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0024          8216 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0025          8217 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0116          8308 68bc.0c61.2f80         4    2   20  15  Gi1/0/1

ce1-top-crml#sh sp roo

                                        Root    Hello Max Fwd
Vlan                   Root ID          Cost    Time  Age Dly  Root Port
---------------- -------------------- --------- ----- --- ---  ------------
VLAN0001          8193 68bc.0c61.2f80         0    2   20  15
VLAN0010          8202 68bc.0c61.2f80         0    2   20  15
VLAN0020          8212 68bc.0c61.2f80         0    2   20  15
VLAN0021          8213 68bc.0c61.2f80         0    2   20  15
VLAN0022          8214 68bc.0c61.2f80         0    2   20  15
VLAN0023          8215 68bc.0c61.2f80         0    2   20  15
VLAN0024          8216 68bc.0c61.2f80         0    2   20  15
VLAN0025          8217 68bc.0c61.2f80         0    2   20  15
VLAN0116          8308 68bc.0c61.2f80         0    2   20  15

----------------------------------------------------------------------------
-------------

CE2  ----------- stp works in this direction for vlan 1 -------->>>  CE1
(from ce2 to ce1)

Ce1 *does* see vlan 1 config bpdu's carrying superior bridge prio of 4097

ce2-realnoc#conf t
ce2-realnoc(config)#spanning-tree vl 1 priority 4096
ce2-realnoc(config)#^Z
ce2-realnoc#sh sp roo
*Mar  2 18:58:12.604: %SYS-5-CONFIG_I: Configured from console by console

                                        Root    Hello Max Fwd
Vlan                   Root ID          Cost    Time  Age Dly  Root Port
---------------- -------------------- --------- ----- --- ---  ------------
VLAN0001          4097 68bc.0c61.3a80         0    2   20  15
VLAN0010          8202 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0020          8212 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0021          8213 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0022          8214 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0023          8215 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0024          8216 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0025          8217 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
VLAN0116          8308 68bc.0c61.2f80         4    2   20  15  Gi1/0/1
ce2-realnoc#


ce1-top-crml#sh sp roo

                                        Root    Hello Max Fwd
Vlan                   Root ID          Cost    Time  Age Dly  Root Port
---------------- -------------------- --------- ----- --- ---  ------------
VLAN0001          4097 68bc.0c61.3a80         4    2   20  15  Gi1/0/1
VLAN0010          8202 68bc.0c61.2f80         0    2   20  15
VLAN0020          8212 68bc.0c61.2f80         0    2   20  15
VLAN0021          8213 68bc.0c61.2f80         0    2   20  15
VLAN0022          8214 68bc.0c61.2f80         0    2   20  15
VLAN0023          8215 68bc.0c61.2f80         0    2   20  15
VLAN0024          8216 68bc.0c61.2f80         0    2   20  15
VLAN0025          8217 68bc.0c61.2f80         0    2   20  15
VLAN0116          8308 68bc.0c61.2f80         0    2   20  15




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