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Webcast-Catalyst9k
New Member

Few Vlan down when Core Down (SPT and HSRP Problem)

 

Hi all, i want to edit my question,

I have 2 core switch with HSRP, just say CoreA and CoreB,

The problem start when our main electricity down and this is made CoreB Down (CoreA still UP) and we used secondary electricity for CoreB and all vlan is working properly but only voice vlan is down, this is happend because when CoreB going UP, the CoreB act as Active too like CoreA  (Should be the CoreA as Active) so the traffic is intermittent.

When our primary electricity back to normal, we switch electricity CoreB from secondary electricity to primary electricity and then all vlan is working properly and the problem that happend before not show up anymore.

 

This is my capture configuration:

CoreA:
spanning-tree mode pvst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
spanning-tree vlan 1-900 priority 8192

interface Vlan16
 description VLAN Voice A
 ip address 192.168.16.2 255.255.255.0
 ip helper-address 192.168.192.34
 no ip proxy-arp
 ip pim dr-priority 100
 ip pim sparse-mode
 standby 16 ip 192.168.16.1
 standby 16 preempt
!
interface Vlan19
 description VLAN Voice B
 ip address 192.168.17.2 255.255.255.0
 ip helper-address 192.168.192.34
 no ip proxy-arp
 ip pim dr-priority 100
 ip pim sparse-mode
 standby 17 ip 192.168.17.1
 standby 17 preempt
!
and other vlan configuration
!

 

CoreB:
spanning-tree mode pvst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
spanning-tree vlan 1-900 priority 28672

interface Vlan16
 description VLAN Voice A
 ip address 192.168.16.3 255.255.255.0
 ip helper-address 192.168.192.34
 no ip proxy-arp
 ip pim dr-priority 90
 ip pim sparse-mode
 standby 16 ip 192.168.16.1
 standby 16 priority 90
 standby 16 preempt
!
interface Vlan19
 description VLAN Voice B
 ip address 192.168.17.3 255.255.255.0
 ip helper-address 192.168.192.34
 no ip proxy-arp
 ip pim dr-priority 90
 ip pim sparse-mode
 standby 17 ip 192.168.17.1
 standby 17 priority 90
 standby 17 preempt
!
and other vlan configuration
!

 

* Sorry i change the question because i have wrong information before

 

Thanks,

 

7 REPLIES
Cisco Employee

The logs are all EIGRP,

The logs are all EIGRP, should EIGRP be used?

Are we talking about L2 or L3 traffic? Do you have any phone using this vlan connected directly to CORE_A?

Can you check spanning-tree when CORE_B is up and when it is down?
 

 

 

Bronze

If you have an interface that

If you have an interface that is the only interface in a vlan and that physical interface is down the vlan will go down as well.   

This is called vlan autostate if you want to check into it deeper.    This could also tie into why you are seeing L3 events with EIGRP.  Not sure... post some more details if you are still seeing this happen.  Also, a topology print would be helpful.

- Be sure to rate all helpful posts

HelloSh ip eigrp neighboursSh

Hello

Sh ip eigrp neighbours
Sh ip route eigrp
Sh ip protocols
Sh run |  be router eigrp

res

Paul

Please don't forget to rate any posts that have been helpful. Thanks.
New Member

Adding more to Renan, I could

Adding more to Renan, I could not make it clear whether it was an issue with the power supply. The problem was with the standby/seconday electric supply only.

 

It seems the secondary power supply was not serving enough to get all the configured hardware/software configs come up.

Further, if you are still facing troubles, can you confirm if the switch with problematic vlan can serve it locally ( a direct connected host ) ?

 

-- 

Parvesh

New Member

Parver, I'm not talking about

Parver, I'm not talking about power supply, the problem is why the CoreA and CoreB act as Active after the CoreB down.

HelloWhat make/model are

Hello

What make/model are these cores switches?

To get active - active in hsrp peering, a lost of periodic hellos have been incurred, so this seems to suggest your cores lost connectivity between each other .

Possible reasons -

STP convergence
Routing protocol convergence
Physical issue

 

On a side note, looking at your post , I see you have pvst+ enabled which is not optimal stp - I would suggest using RSTP ( faster convergence timings) Also you have default delay values for HSRP)

 

res

Paul 

 

Please don't forget to rate any posts that have been helpful. Thanks.
New Member

Dear arikawahyono, Hope it

Dear

 

 

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