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interface flapping in Cat3560 and routers

bluejays (TechnicalUser)
30 Jun 05 23:06
Hi, there, I have a interface flapping issue in my network. 2 Cat3560 is connected through 2 trunk port configured with port-channel. When I shutdown one of port in Vlan100, other 2 ports in the same vlan will flap going up and down and OSPF will lose the neighbor. One thing I notice that is when I shutdown the switch port, on the other side of router, the L1-L2 is still up/up. I think it should be up/down. I have a keepalive setting on the router interface to 1800. Any body can give me some hints here to troubleshoot?
Here is the switch configs.
Building configuration...

Current configuration : 4453 bytes
!
version 12.2
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname RCHdmzSW01
!
logging buffered 8192 debugging
!
ip subnet-zero
ip routing
!
no ip domain-lookup
!
spanning-tree mode pvst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
!
!
!         
!
!
interface Port-channel1
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 999
 switchport trunk allowed vlan 100,200,300,400,600,700
 switchport mode trunk
!
interface GigabitEthernet0/1
 switchport access vlan 600
 speed 100
 duplex full
!
interface GigabitEthernet0/2
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/3
 switchport access vlan 600
 speed 100
 duplex full
!         
interface GigabitEthernet0/4
 switchport access vlan 700
 speed 100
 duplex full
!
interface GigabitEthernet0/5
 switchport access vlan 700
 speed 100
 duplex full
!
interface GigabitEthernet0/6
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/7
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/8
 switchport access vlan 100
!         
interface GigabitEthernet0/9
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/10
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/11
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/12
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/13
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/14
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/15
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/16
 switchport access vlan 100
 speed 100
 duplex full
!
interface GigabitEthernet0/17
 speed 100
 duplex full
!
interface GigabitEthernet0/18
!         
interface GigabitEthernet0/19
!
interface GigabitEthernet0/20
!
interface GigabitEthernet0/21
!
interface GigabitEthernet0/22
!
interface GigabitEthernet0/23
!
interface GigabitEthernet0/24
!
interface GigabitEthernet0/25
!
interface GigabitEthernet0/26
!
interface GigabitEthernet0/27
 switchport access vlan 400
!
interface GigabitEthernet0/28
 switchport access vlan 400
!
interface GigabitEthernet0/29
 switchport access vlan 400
!
interface GigabitEthernet0/30
 switchport access vlan 200
!
interface GigabitEthernet0/31
 switchport access vlan 200
!
interface GigabitEthernet0/32
 switchport access vlan 200
!
interface GigabitEthernet0/33
 switchport access vlan 200
!
interface GigabitEthernet0/34
 switchport access vlan 200
!
interface GigabitEthernet0/35
 switchport access vlan 200
!
interface GigabitEthernet0/36
 switchport access vlan 200
!         
interface GigabitEthernet0/37
 switchport access vlan 200
!
interface GigabitEthernet0/38
 switchport access vlan 200
!
interface GigabitEthernet0/39
 switchport access vlan 200
!
interface GigabitEthernet0/40
 switchport access vlan 200
!
interface GigabitEthernet0/41
 switchport access vlan 200
!
interface GigabitEthernet0/42
 switchport access vlan 200
!
interface GigabitEthernet0/43
 switchport access vlan 200
!
interface GigabitEthernet0/44
 switchport access vlan 200
!
interface GigabitEthernet0/45
 switchport access vlan 500
 speed 100
 duplex full
!
interface GigabitEthernet0/46
 switchport access vlan 500
 speed 100
 duplex full
!
interface GigabitEthernet0/47
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 999
 switchport trunk allowed vlan 100,200,300,400,600,700
 switchport mode trunk
 channel-group 1 mode on
!
interface GigabitEthernet0/48
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 999
 switchport trunk allowed vlan 100,200,300,400,600,700
 switchport mode trunk
 channel-group 1 mode on
!
interface GigabitEthernet0/49
!
interface GigabitEthernet0/50
!
interface GigabitEthernet0/51
!
interface GigabitEthernet0/52
!
interface Vlan1
 no ip address
 shutdown
!
interface Vlan100
 ip address 192.168.40.11 255.255.252.0
 no ip redirects
 no ip proxy-arp
 standby 1 ip 192.168.40.1
 standby 1 priority 110
 standby 1 preempt
 standby 1 track Vlan600 20
!         
interface Vlan200
 no ip address
!
interface Vlan600
 ip address 192.168.35.1 255.255.255.0
!
router ospf 7
 log-adjacency-changes
 network 192.168.0.0 0.0.255.255 area 0
!
ip classless
ip http server
!
!
!
control-plane
!
!
line con 0
line vty 5 15
!
end

When I shutdown interface gig 0/2, interface gig0/3 and gig0/4 will go down as well and come back online after a while.

Thanks for your help.
bluejays (TechnicalUser)
30 Jun 05 23:14
The topology is like the following.

                      V100 (192.168.43.0)
              -----------------------------
               |                        |
               |                        |
               |                        |
         |----------|    Trunk      |----------
         |  SW1     |---------------|  SW2    |
          -----------               ----------
           |   |   | V600              | | | V700
           |   |   |                   | | |
           |   |   |-------R1----------- | |
           |   |-----------R2------------- |
           |---------------R3---------------
lambent (Vendor)
3 Jul 05 22:02
What's your IOS version?
bluejays (TechnicalUser)
6 Jul 05 1:32
What did you suspect? I will confirm the IOS version tomorrow. However, I am leaning toward the Port-channel command. Since it has etherchannel configured and set the mode to "ON", it might cause the spanning-tree loop as per Cisco's Document if the etherchannel is misconfigured.
I saw the spanning-tree on VLAN 600 will do the spanning-tree calculation 2 times when I shut some port belongs to VLAN 600.
I also noticed that some VLAN assignment to the port is not correct, will double-check tomorrow.

Thanks.
lambent (Vendor)
6 Jul 05 2:01
"mode on" only means that you don't use PAgP/LACP for channel negotiation. Make sure both sides are set to "mode on".

And in older IOS image for Catalyst switches, it has bugs in STP/RSTP/MSTP so it'll be good to make sure that all Catalyst switches are running the most up-to-date IOS version (this may not necessarily be the same case for routers).
bluejays (TechnicalUser)
8 Jul 05 4:05
The IOS is 12.2(20)SE4. c3560-i5-mz.122-20.SE4.bin
BOOT IOS is 12.2(25r)SE.

It is not the latest, but it should be close enough. Any thought?
lambent (Vendor)
8 Jul 05 4:13
Cisco IOS         Date Retired
12.2(20)SE4    12-MAY-2005

I can only find 12.2.25-SEB2 which is the most updated release as of today and which doesn't have any "Software Advisory Notice"....yet.

I suggest you should try upgrading your IOS to the most current version and try again. At least this is what you can do at this moment.
bluejays (TechnicalUser)
18 Jul 05 23:07
It is a bug in the IOS, Thanks. I got the TAC confirmed from Cisco

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